After studying the letter to the church in Ephasus it may benefit our understanding of the church as the body of Christ, the congregation, before we proceed to the other letters.

The doctrine of the church

The question what is the Church, presupposes its existence, so there is no necessity for us to prove that there is a church.  It is clear according to Scripture that there always has been, and ever will be a church, because Christ always has been, and always will be King, Head, and Priest of the church, as we shall see in this part of the study.

The term church comes from an ancient Greek word ekklesia, which meant to call forth an assembly of citizens by the voice of a public crier, from a crowd for the purpose of hearing an oration, or a decision of the Senate.

The Apostles used the word ekklesia for the purpose of expressing the assembly of the church.  The church is an assemblage of persons brought together, not by chance, nor in a disorderly manner, but called out of the kingdom of Satan by the voice of the Lord, and by the preaching of the gospel for the purpose of hearing, and embracing the word of God.

The word synagogue also signifies an assembly but with one major, and crucial, distinction: synagogue means any kind of assembly or gathering, however common, and irregularly brought together.  Ecclesia, on the other hand, denotes a congregation called together in a particular manner, and for a particular purpose, which is the character of the congregation of those who are called by God to a knowledge of the gospel.

There is a distinction between the word church meaning ecclesia, the assembly of the people of God, and the word church meaning the building in which the church (ecclesia) assemble.  The Middle English chirche comes from the Old English cirice, ultimately from Medieval Greek kurikon, from Late Greek kuriakon (doma) meaning the Lord's (house) and from Greek kuriakos (of the Lord) or kurios (Lord). In German, the word used is Kirche while the building (kuriakos) is also described as Gotteshaus, which literally means God's house.  In Latin the Greek word ecclesia is used.

The church is that assembly, chosen of God, from everlasting to eternal life, which the Son of God, from the beginning to the end of the world, gathers, defends and preserves to himself, by his Spirit and word, out of the whole human race, agreeing in true faith, and which he will at length glorify with eternal life and glory. This is the definition of the true church of God to which the Apostle's Creed refers.

We ought not to ascribe to the church (kuriakos) any special meaning that belongs to the church (ekklesias).  Calling the assembly of Christ a 'church' has certain pitfalls that the believer should avoid, such as that the use of the term 'church' should adopt an identity of its own in conflict with the true meaning of ekklesia, which is the body of Christ.  The church building might evolve in people's minds as a holy place that has a mysterious value, which may lead to idolatry.  The power of the church, as exerciser of discipline and the keys of the kingdom of heaven, may project and even instill a perception in the congregation that the church has local, visible powers that she does not have, but actually usurped powers that belong to Christ alone.  It is, therefore, the duty of the elders, and the congregation, to guard against slowly changing perceptions that could, over time, shift the focus of the assembly away from the body of Christ towards becoming nothing more than a house of idol worship. That, after all, is nothing less than the ultimate goal of the workers of unrighteousness. The rule and yardstick by which the direction of the church and the perceptions that are formed are measured, is Scripture alone.

There is a specific relationship of cause and effect that ought to rule our understanding of the church, which is Christ is the First Cause and the church is the effect.  We congregate as a body because of Christ and for no other reason, so that there would be no ambiguity about the Cause and the effect. As soon as the visible church's identity shifts from that of an effect, reflecting nothing but Jesus, adopting an identity of a cause, it claims for itself properties which will inescapably be in conflict with the image of Christ, extinguishing the light of the lampstand.

How manifold is the Church?

The church is either true or false.  To speak of a false church as church is to use the word improperly.  A false church is an assembly, which assumes the name Christian Church but instead of following it, rather persecutes it.

The true church is either triumphant or militant.  It is triumphant in which it will at length obtain a complete triumph after the resurrection.  The Church Triumphant is even now triumphant as it glorifies God in the promise and hope of the Gospel.

It is militant in which it fights in this world under the banner of Christ against the devil, the flesh and the world.  The church militant is either visible or invisible.  When spoken of as visible, it means an assembly of persons, who embrace and profess the entire and uncorrupted doctrine of the law and the Gospel, and who use the sacraments according to the appointment of Christ, and profess obedience to the teachings of God’s word.

The visible church consists of many who are regenerated by the Holy Spirit through the word unto eternal life, and many also who are hypocrites and unregenerated, but who nevertheless consent to the doctrine, and conform to the external rites of the church.

The visible church may be defined to be the assembly of those who assent to the doctrine of God’s word, among whom there are many dead members, or such as have not been regenerated.

Habakkuk 1:13 - 17 Your eyes are too pure to look on evil; you cannot tolerate wrong. Why then do you tolerate the treacherous? Why are you silent while the wicked swallow up those more righteous than themselves? ¹⁴You have made men like fish in the sea, like sea creatures that have no ruler. ¹⁵The wicked foe pulls all of them up with hooks, he catches them in his net, he gathers them up in his dragnet; and so he rejoices and is glad. ¹⁶Therefore he sacrifices to his net and burns incense to his dragnet, for by his net he lives in luxury and enjoys the choicest food. ¹⁷Is he to keep on emptying his net, destroying nations without mercy?

Matthew 7:21 - 23 "Not everyone who says to me, 'Lord, Lord,' will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. ²²Many will say to me on that day, 'Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?' ²³Then I will tell them plainly, 'I never knew you. Away from me, you evildoers!'

Matthew 13:24 - 30 Jesus told them another parable: "The kingdom of heaven is like a man who sowed good seed in his field. ²⁵But while everyone was sleeping, his enemy came and sowed weeds among the wheat, and went away. ²⁶When the wheat sprouted and formed heads, then the weeds also appeared. ²⁷The owner's servants came to him and said, 'Sir, didn't you sow good seed in your field? Where then did the weeds come from?' ²⁸'An enemy did this,' he replied. The servants asked him, 'Do you want us to go and pull them up? ²⁹'No,' he answered, 'because while you are pulling the weeds, you may root up the wheat with them. ³⁰Let both grow together until the harvest. At that time I will tell the harvesters: First collect the weeds and tie them in bundles to be burned; then gather the wheat and bring it into my barn.'

Matthew 13:47 - 50 Once again, the kingdom of heaven is like a net that was let down into the lake and caught all kinds of fish. ⁴⁸When it was full, the fishermen pulled it up on the shore. Then they sat down and collected the good fish in baskets, but threw the bad away. ⁴⁹This is how it will be at the end of the age. The angels will come and separate the wicked from the righteous ⁵⁰and throw them into the fiery furnace, where there will be weeping and gnashing of teeth."

The invisible church consists of those who are chosen unto eternal life, who are also regenerated, and belong to the visible church.  It lies concealed in the visible church, during the whole of the struggle, and conflict which is continually going on in this world between the kingdom of light and darkness.  It is also called the church of the saints.  Those who belong to this church never perish; neither are there any hypocrites in it for it consists only of such as are chosen unto eternal life.

John 10:28 I give them eternal life, and they shall never perish; no one can snatch them out of my hand.

II Timothy 2:19 Nevertheless, God's solid foundation stands firm, sealed with this inscription: "The Lord knows those who are his," and, "Everyone who confesses the name of the Lord must turn away from wickedness."

It is called invisible, not because the members are invisible, but because the faith and piety of those who belong to it can neither be seen, nor known, except by those who possess it and also because we cannot with certainty distinguish the godly from those who are hypocrites in the visible church.

Furthermore, the church, both visible and invisible, is either universal or particular.

The universal visible church consists of all those who profess the doctrine of God’s word, in whatever part of the world they may be.

The particular visible church is those who, in any particular place, profess this doctrine.  The visible church is universal in as far as it respects to place and diversity of rites and ceremonies.  Similarly, the invisible church is universal, inasmuch as all the elect, wherever they may be, and in whatever time they may have lived, have one faith, and it is particular inasmuch as they have the same faith.

All the particular churches are parts of the universal church and the different parts of the visible belong to the universal visible church.  Similarly, the invisible are parts of the universal invisible church. 

It is of this universal invisible church of which this article of the Creed speaks, saying, I believe in the holy catholic church.

These properties are also attributed with great propriety to the church, because it is holy, and because it is here that we find the true communion of the saints with Christ and all his members.  The difference which exists between the visible and invisible church is very nearly the same as that which exists between the whole and a part.  The invisible church is concealed in the visible, as a part in the whole.

Romans 8:30 And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.

The parts that are visible have respect to the persons who are called, in as far as they are people, and profess the doctrine of the visible church.  That which pertains to their piety, or their faith and repentance, is invisible.

The calling mentioned in Rom. 8:30, which God addresses to men, is two-fold, inward and outward.  Paul declares that the inward call is made according to the purpose of salvation.  The elect are called in both respects, whilst hypocrites have nothing more than the mere external call.  It is in respect to this outward call that the visible church is termed the church of the called, in which hypocrites are also found.  The invisible church is called the church of the elect.

If the members of the church do not perish, and many hypocrites belong to the church, does it mean that hypocrites will not perish?  No it does not.  Those who belong to the invisible church will not perish and it is of this that the foregoing definition speaks.  There are no hypocrites in the invisible church but there are many hypocrites in the visible church.

Was there a visible church during the reign of the Papal system?  Yes there was.  There have always been some, even in the most corrupt period of the church, who held fast to the fundamental principles of the gospel.  The church was oppressed, but not destroyed.

Matthew 16:18, 19 And I tell you that you are Peter, and on this rock I will build my church, and the gates of Hades will not overcome it. ¹⁹I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven.

There is also another division of the church, namely, into the church of the Old and New Testaments.  The church of the Old Testament included those who received the doctrine of Moses and the Prophets, and professed that they would conform to, and preserve the ceremonies of Moses, and that they would, both among themselves, and among other nations, believe those things which were signified by these institutions that pointed to the Messiah which was to come.

The church of the New Testament believe in the Messiah already come.  It may be defined as the congregation of those who receive the doctrine of the gospel, observe the sacraments instituted by Christ, and believe in him as the true Messiah.

What are the marks of the true Church?

There are three marks, or signs, by which the true church may always be known.

A profession of the true, pure, and rightly understood doctrine of the law and the gospel, which is the same thing as the doctrine of the prophets and apostles.

The right and proper use of the sacraments.  One of the objects of the sacraments, is to distinguish the true church of God from all the various sects and heretics.

The profession of obedience to this doctrine, or to the ministry.

These three things, which are always found in connection with the true church, are contained in the declaration of Christ, where he says, in

Matthew 28:19, 20 Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit ²⁰and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.

It behooves us to hold fast to these marks for the glory of God, that his enemies may be distinguished from his children and also for our salvation, that we may associate ourselves with the true church.

It is also our duty to continually evaluate the measure of steadfastness that the church holds to these signs, that the church may not wander from the true gospel.  This on-going renewal is the result of the working of the Holy Spirit in the members of the church in which they persevere with prayer, patience, faith, and hope; strengthen one another, worship God in their lives, and desire for His Kingdom to come.

Do the great errors, both public and private, that have been found in the church, conflict with the signs of the true church?  No, it does not.  The true foundation of the church has always been preserved, upon which some have built gold, and others straw.

I Corinthians 3:11 - 15 For no one can lay any foundation other than the one already laid, which is Jesus Christ. ¹²If any man builds on this foundation using gold, silver, costly stones, wood, hay or straw, ¹³his work will be shown for what it is, because the Day will bring it to light. It will be revealed with fire, and the fire will test the quality of each man's work. ¹⁴If what he has built survives, he will receive his reward. ¹⁵If it is burned up, he will suffer loss; he himself will be saved, but only as one escaping through the flames.

The church has never defended these errors, hence, the mere fact that errors have been found, does not conflict with the marks of the true church.  It is rather an admonishment to preserve a listening watch for any foreign doctrine or rituals that may cause the church to err again.  Any slight or innocent deviation in doctrine or practice, must raise the alarm and be rectified (renewed) so that the church has no other beacon to steer by, but the pure word of God.

Can we say that obedience is a mark of the true church if there have been many and great sins committed in churches professing the true doctrine of God’s word?  Yes, we can.  There are many in these same churches who do yield, and who strive to yield obedience to the requirements of God’s word; and who confess and acknowledge their sins, so that these things are not defended, but deplored by the church.  It is also necessary that obedience is one of the marks of a true church, lest God should be mocked by those who might say that they receive the doctrine of Christ, and are yet unwilling to live in accordance with it.

What about Heretics and Schismatics[1] who claim to have these marks of the true church?  It is not important what they claim, but rather whether they really posses them.

Is the ordinary succession of ministers not also a mark of the true church since it is a necessary element to the existence of the church in the world?  If the ordinary succession of ministers refers to the succession of the ministry in the same true doctrine of the church and administration of the sacraments, then the answer is: yes, it is.  But if by ordinary succession is meant a succession in the same place, whether they teach the same or different doctrines, and if it is regarded as tying or restricting the church to a certain place, city, or region, then the answer is: no, it is not.

Why is it called one, holy, and catholic?

The Church is one, not because those who are members thereof dwell together, or because the rites and ceremonies to which they conform are the same; but on account of their agreement in doctrine, and faith.  It is called holy, because God sanctifies it by the blood and Spirit of Christ, that it may be conformable to him, not in perfection, but by the imputation of Christ's righteousness, or obedience. 

It is called holy by having the principle of holiness, because the Holy Spirit renews and delivers the church from the dregs of sins by degrees, in order that all who belong to it may commence and practice all the parts of obedience.

It is also called holy, because it is consecrated to a holy and divine use, and is separated from the ungodly.

The Church is called catholic, firstly, in respect to place because it is spread over the whole world, and is not tied or restricted to any particular place, kingdom, or certain succession.  The catholicity of the church, in this respect, commenced at the time of the Apostles; because prior to this time the church was circumscribed in narrow limits, being confined to a particular people.

Secondly, in respect to men, because the church is gathered from all classes of men of every nation.

Thirdly, in respect to time, because it will endure throughout every period of the world.

Deuteronomy 31:6, 8 Be strong and courageous. Do not be afraid or terrified because of them, for the LORD your God goes with you; he will never leave you nor forsake you. ⁸The LORD himself goes before you and will be with you; he will never leave you nor forsake you. Do not be afraid; do not be discouraged.

And because there is only one true Church of all times, which is of such a constitution as to embrace the whole world, and not to be tied down to any one particular place.

It is clear that there can be only one church of all times, from the beginning to the end of the world, for it is clear that the church has always existed, even before the time of Abraham.  It is not to be supposed that the family of Abraham did not worship God before his calling, and that he was only after his calling the servant of the most High. Even before he was called, he held fast to the fundamental principles of the doctrine of the true God, although they were not clearly understood, on account of the false notions and superstitions which were mingled with them.

Before Abraham there were other worshippers of the true God, such as Adam, before and after the fall, Abel, and Seth.

The church will always exist, as Scripture teaches us. 

Isaiah 59:21  "As for me, this is my covenant with them," says the LORD. "My Spirit, who is on you, and my words that I have put in your mouth will not depart from your mouth, or from the mouths of your children, or from the mouths of their descendants from this time on and forever," says the LORD.

Jeremiah 33:20, 21 "This is what the LORD says: 'If you can break my covenant with the day and my covenant with the night, so that day and night no longer come at their appointed time. ²¹Then my covenant with David my servant--and my covenant with the Levites who are priests ministering before me--can be broken and David will no longer have a descendant to reign on his throne.

Matthew 28:20 And teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.

Christ always has been, and always will be King, Head and Priest of the church.  Hence there always has been, and ever will be a church.  It is also evident that the church, both of the Old and New Testaments, is one and the same; which is also confirmed by the next article of the Creed.

Christ is the sanctifier of his church, and is common to those who have believed in him under each dispensation.

It is necessary that we consider the authority of the church here.  The authority of the church is not greater than that of the Scriptures for the church did not produce the Scriptures but the Scriptures (Gospel) gave birth to the church.

Churches may be deviated from the true gospel by the influence and authority of tradition.  Tradition manifests only after prolonged practice and usually surfaces in the action of future generations.  Paul says in

I Corinthians 15:3  For what I received I passed on to you …

It is the passing on of a tradition.  But if we read on a little further to the place where Paul explains what those things are, we read:

I Corinthians 15:3 - 5 …as of first importance: that Christ died for our sins according to the Scriptures, ⁴that he was buried, that he was raised on the third day according to the Scriptures,  ⁵and that he appeared to Peter, and then to the Twelve.

The traditions of Paul was according to the Scriptures and not from his ancestors or his own perception of traditional worship.  They were first taken from the Scriptures of the Old Testament and then they were committed to writing by Paul himself.

Concerning the Lord’s Supper, Paul says

I Corinthians 11:23  For I received from the Lord what I also passed on to you: The Lord Jesus, on the night he was betrayed, took bread.

But this tradition the Apostle himself also committed to writing as a result of Divine inspiration. 

In the following passage, Paul again speaks of tradition:

II Thessalonians 3:6  In the name of the Lord Jesus Christ, we command you, brothers, to keep away from every brother who is idle and does not live according to the teaching you received from us,

which is clearly explained further on in the chapter which tradition he meant by declaring that he himself taught them and wrote these passages as Apostle, Divinely inspired to write the gospel.

Tradition has been the vehicle of many deviations of the church, as Scripture warns us in

Mark 7:13 Thus you nullify the word of God by your tradition that you have handed down. And you do many things like that.

Colossians 2:8  See to it that no one takes you captive through hollow and deceptive philosophy, which depends on human tradition and the basic principles of this world rather than on Christ.

Colossians 2:20 - 23 Since you died with Christ to the basic principles of this world, why, as though you still belonged to it, do you submit to its rules: ²¹"Do not handle! Do not taste! Do not touch!" ²²These are all destined to perish with use, because they are based on human commands and teachings. ²³Such regulations indeed have an appearance of wisdom, with their self-imposed worship, their false humility and their harsh treatment of the body, but they lack any value in restraining sensual indulgence.

The diligent clinging of the church to the true teaching of Scripture is the only assurance that human tradition will not cause even the slightest deviation, which will aggravate as time passes.

Some safeguards against deviations may be suggested here. 

The elders must continually discern the conformity of the preached word to the Scriptures and have no fear or apprehension to confront any deviation from Scripture according to Matt 18.

The church must diligently guard against the abuse of the sacraments, and oversee the proper and timely exercise thereof.

The church must exercise the discipline which it is entrusted with according to Matt. 18 and not hesitate to fulfill its calling in this regard.

Any traditions or ceremonies in the church must be subjected to careful scrutiny to determine whether they are founded in Scripture or Church Order.

In what does the Church differ from the state?

The main differences between the church and the state are the following:

The state is a society which is bound by certain civil laws for the maintenance of external propriety and order.  The church consists of those who embrace the gospel, and observe the sacraments according to divine appointment, and is governed by the Spirit and Word of God, requiring both internal and external obedience.

In the church there are always some holy and godly persons, which is not always true of the state.

There are many and different states which are distinguished from each other by locality, time and laws.  There is not a universal state of which all the other states are part.  The church, however, has been, is, and ever will be, one throughout all periods, and among all nations.  It is for this reason called Catholic, universal, having many parts.

The head of the church is one, and in heaven, which is Christ.  The different states have many heads and rulers and they are all here on earth.

The state has magisterial authority and power to make laws, to which it becomes us to yield obedience for conscience sake.  The church is restricted and tied down to the word of God, and has no power to make new articles of faith.  It may establish rules of order and propriety, but without binding the conscience.  It may do so only with consent and not magisterial authority.

The state is armed with power to inflict punishment upon offenders, and to preserve its laws with the sword.  The church has merely the sword of the word, which consists in the denunciation of the wrath of God against those who are disobedient.  One and the same person, as the prophets and priests of old, may sometimes act both in a civil and ecclesiastical capacity.  Hence they ought to be carefully distinguished.

Psalm 2:10 - 12 Therefore, you kings, be wise; be warned, you rulers of the earth. ¹¹Serve the LORD with fear and rejoice with trembling. ¹²Kiss the Son, lest he be angry and you be destroyed in your way, for his wrath can flare up in a moment. Blessed are all who take refuge in him.

As we can see from the differences between church and state, it would be a grave threat to the church, and the state, if either party were to compromise their specific roles and characters in order to conform to the other.

The church has to admonish the state to protect the church as nursing fathers,[2]

Isaiah 49:23 Kings will be your foster fathers, and their queens your nursing mothers. They will bow down before you with their faces to the ground; they will lick the dust at your feet. Then you will know that I am the LORD; those who hope in me will not be disappointed.

Romans 13:1 - 7 Everyone must submit himself to the governing authorities, for there is no authority except that which God has established. The authorities that exist have been established by God. ²Consequently, he who rebels against the authority is rebelling against what God has instituted, and those who do so will bring judgment on themselves. ³For rulers hold no terror for those who do right, but for those who do wrong. Do you want to be free from fear of the one in authority? Then do what is right and he will commend you. ⁴For he is God's servant to do you good. But if you do wrong, be afraid, for he does not bear the sword for nothing. He is God's servant, an agent of wrath to bring punishment on the wrongdoer. ⁵Therefore, it is necessary to submit to the authorities, not only because of possible punishment but also because of conscience. ⁶This is also why you pay taxes, for the authorities are God's servants, who give their full time to governing. ⁷Give everyone what you owe him: If you owe taxes, pay taxes; if revenue, then revenue; if respect, then respect; if honor, then honor.

The state may regulate the civil activities of the church, to which the church should yield obedience, without binding the conscience, since all power is from God.

The state may not assume to itself the administration of the Word and sacraments or the power of the keys of the kingdom of heaven, or in the least interfere in the matters of faith.

II Chronicles 26:18 They confronted him and said, "It is not right for you, Uzziah, to burn incense to the LORD. That is for the priests, the descendants of Aaron, who have been consecrated to burn incense. Leave the sanctuary, for you have been unfaithful; and you will not be honored by the LORD God."

Matthew 18:17 If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, treat him as you would a pagan or a tax collector.

I Corinthians 12:28, 29 And in the church God has appointed first of all apostles, second prophets, third teachers, then workers of miracles, also those having gifts of healing, those able to help others, those with gifts of administration, and those speaking in different kinds of tongues. ²⁹Are all apostles? Are all prophets? Are all teachers? Do all work miracles?

Ephesians 4:11, 12 It was he who gave some to be apostles, some to be prophets, some to be evangelists, and some to be pastors and teachers. ¹²To prepare God's people for works of service, so that the body of Christ may be built up.

I Corinthians 4:1, 2 So then, men ought to regard us as servants of Christ and as those entrusted with the secret things of God. ²Now it is required that those who have been given a trust must prove faithful.

Romans 10:15 And how can they preach unless they are sent? As it is written, "How beautiful are the feet of those who bring good news!"

Hebrews 5:4 - 6 No one takes this honor upon himself; he must be called by God, just as Aaron was. ⁵So Christ also did not take upon himself the glory of becoming a high priest. But God said to him, "You are my Son; today I have become your Father." ⁶And he says in another place, "You are a priest forever, in the order of Melchizedek."

John 18:36  Jesus said, "My kingdom is not of this world. If it were, my servants would fight to prevent my arrest by the Jews. But now my kingdom is from another place."

Acts 5:29  Peter and the other apostles replied: "We must obey God rather than men."

Jesus Christ appointed a regular government and discipline in his Church, and no law or state should interfere with, let, or hinder, the due exercise thereof, among its voluntary members, regardless of the denomination, according to their own profession and belief.

It is the duty of the state to protect the person and good name of all its people, in such a manner that no person shall suffer any indignity, violence, abuse, or injury on account of religion or conviction of faith.  It is further the duty of the state to guarantee that all religious and ecclesiastical assemblies be held without molestation or disturbance.

Romans 13:4 For he is God's servant to do you good. But if you do wrong, be afraid, for he does not bear the sword for nothing. He is God's servant, an agent of wrath to bring punishment on the wrongdoer.

It is the duty of the church to pray for the state,

I Timothy 2:1, 2  I urge, then, first of all, that requests, prayers, intercession and thanksgiving be made for everyone-²for kings and all those in authority, that we may live peaceful and quiet lives in all godliness and holiness.

to honor their persons,

I Peter 2:17 Show proper respect to everyone: Love the brotherhood of believers, fear God, honor the king.

to pay them tribute or other dues,

Romans 13:6, 7  This is also why you pay taxes, for the authorities are God's servants, who give their full time to governing. ⁷Give everyone what you owe him: If you owe taxes, pay taxes; if revenue, then revenue; if respect, then respect; if honor, then honor.

to obey their lawful commands, and to be subject to their authority, for conscience’s sake.

Romans 13:5 Therefore, it is necessary to submit to the authorities, not only because of possible punishment but also because of conscience.

Titus 3:1  Remind the people to be subject to rulers and authorities, to be obedient, to be ready to do whatever is good.

Differences in religion does not negate the just and legal authority of the state, nor does it free people from their due obedience to them.

I Peter 2:13 - 15 Submit yourselves for the Lord's sake to every authority instituted among men: whether to the king, as the supreme authority ¹⁴or to governors, who are sent by him to punish those who do wrong and to commend those who do right. ¹⁵For it is God's will that by doing good you should silence the ignorant talk of foolish men.

What is the cause of the difference between the Church and the rest of mankind?

There are classes of men in the world, which differ very much from each other.  There are some, who by their own declarations, are so entirely alienated from the church as to deny the necessity of faith and repentance, and are, therefore, the avowed enemies of God and the church.  There are others who are called, but not effectually, as hypocrites, who make a profession of faith without any true conversion to God.  And, finally, there are others who are effectually called, such as the elect, of which there are only a few.

Matthew 7:13, 14  "Enter through the narrow gate. For wide is the gate and broad is the road that leads to destruction, and many enter through it. ¹⁴But small is the gate and narrow the road that leads to life, and only a few find it."

Matthew 22:14  "For many are invited, but few are chosen."

Luke 13:24 "Make every effort to enter through the narrow door, because many, I tell you, will try to enter and will not be able to."

What is the cause of this difference?  The efficient cause of this difference is the election of God, who purposed to gather to himself in this world a church.  The Son of God is the mediate executor of the will of the Father, while the Holy Spirit is the immediate executor.

The word of God is the instrumental cause

Acts 14:16 In the past, he let all nations go their own way. ¹⁷Yet he has not left himself without testimony: He has shown kindness by giving you rain from heaven and crops in their seasons; he provides you with plenty of food and fills your hearts with joy.

Romans 8:23 Not only so, but we ourselves, who have the firstfruits of the Spirit, groan inwardly as we wait eagerly for our adoption as sons, the redemption of our bodies. ³⁰And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.

Romans 9:1  I speak the truth in Christ--I am not lying, my conscience confirms it in the Holy Spirit.

John 6:37 All that the Father gives me will come to me, and whoever comes to me I will never drive away.

in which we are taught that the promise of grace is general in respect to those that believe.  God does indeed will that all should be saved, and that, both on account of the desire which He has for the salvation of all, and also because He invites all to seek salvation, but only the elect obtains it, the others are blinded.

Romans 11:7, 8  What then? What Israel sought so earnestly it did not obtain, but the elect did. The others were hardened. ⁸As it is written: "God gave them a spirit of stupor, eyes so that they could not see and ears so that they could not hear, to this very day.

Is there any salvation out of the Church?

Ordinarily, no one can be saved out of the Church because: 

out of the church there is no Savior, and hence no salvation. 

John 15:5  "I am the vine; you are the branches. If a man remains in me and I in him, he will bear much fruit; apart from me you can do nothing."

Acts 2:47 Praising God and enjoying the favor of all the people. And the Lord added to their number daily those who were being saved.

those whom God has chosen to the end, which is eternal life, them He has chosen to the means, which consist in the inward and outward call.

The visible church consists of all those throughout the world that profess the true religion;

I Corinthians 1:2  To the church of God in Corinth, to those sanctified in Christ Jesus and called to be holy, together with all those everywhere who call on the name of our Lord Jesus Christ--their Lord and ours.

I Corinthians 12:12, 13  The body is a unit, though it is made up of many parts; and though all its parts are many, they form one body. So it is with Christ. ¹³For we were all baptized by one Spirit into one body--whether Jews or Greeks, slave or free--and we were all given the one Spirit to drink.

Psalm 2:8, 9 Ask of me, and I will make the nations your inheritance, the ends of the earth your possession. ⁹You will rule them with an iron scepter; you will dash them to pieces like pottery.

Revelation 7:9  After this I looked and there before me was a great multitude that no one could count, from every nation, tribe, people and language, standing before the throne and in front of the Lamb. They were wearing white robes and were holding palm branches in their hands.

Romans 15:9 - 12 So that the Gentiles may glorify God for his mercy, as it is written: "Therefore I will praise you among the Gentiles; I will sing hymns to your name." ¹⁰Again, it says, "Rejoice, O Gentiles, with his people." ¹¹And again, "Praise the Lord, all you Gentiles, and sing praises to him, all you peoples." ¹²And again, Isaiah says, "The Root of Jesse will spring up, one who will arise to rule over the nations; the Gentiles will hope in him."

and of their children;

I Corinthians 7:14 For the unbelieving husband has been sanctified through his wife, and the unbelieving wife has been sanctified through her believing husband. Otherwise your children would be unclean, but as it is, they are holy.

Acts 2:39 The promise is for you and your children and for all who are far off--for all whom the Lord our God will call.

Ezekiel 16:20, 21  "'And you took your sons and daughters whom you bore to me and sacrificed them as food to the idols. Was your prostitution not enough? ²¹You slaughtered my children and sacrificed them to the idols.

Romans 11:16 If the part of the dough offered as firstfruits is holy, then the whole batch is holy; if the root is holy, so are the branches.

Genesis 3:15 And I will put enmity between you and the woman, and between your offspring and hers; he will crush your head, and you will strike his heel.

Genesis 17:7 I will establish my covenant as an everlasting covenant between me and you and your descendants after you for the generations to come, to be your God and the God of your descendants after you.

and is the kingdom of the Lord Jesus Christ,

Matthew 13:47, 48  "Once again, the kingdom of heaven is like a net that was let down into the lake and caught all kinds of fish. ⁴⁸When it was full, the fishermen pulled it up on the shore. Then they sat down and collected the good fish in baskets, but threw the bad away."

Isaiah 9:7 Of the increase of his government and peace there will be no end. He will reign on David's throne and over his kingdom, establishing and upholding it with justice and righteousness from that time on and forever. The zeal of the LORD Almighty will accomplish this.

and the house and family of God.

Ephesians 2:19  Consequently, you are no longer foreigners and aliens, but fellow citizens with God's people and members of God's household, ²⁰built on the foundation of the apostles and prophets, with Christ Jesus himself as the chief cornerstone. ¹⁴For this reason I kneel before the Father, ¹⁵from whom his whole family in heaven and on earth derives its name. ¹⁶I pray that out of his glorious riches he may strengthen you with power through his Spirit in your inner being, ¹⁷so that Christ may dwell in your hearts through faith. And I pray that you, being rooted and established in love, ¹⁸may have power, together with all the saints, to grasp how wide and long and high and deep is the love of Christ, ¹⁹and to know this love that surpasses knowledge--that you may be filled to the measure of all the fullness of God.

What is it to believe in one, Holy, Catholic Church? 

It is to believe that there always has been, is, and ever will be, to the end of time such a church in the world, and that in the congregation composing the visible church there are always some who are truly converted, and that I am one of this number; and therefore a member of both the visible and invisible church, and shall forever remain such.