Righteous Oaths of the Kingdom

Rev. VanderWal is pastor of Hope Protestant Reformed Church in Redlands, California.

Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths: But I say unto you, Swear not at all; neither by heaven; for it is God's throne: Nor by the earth; for it is his footstool: neither by Jerusalem; for it is the city of the great King. Neither shalt thou swear by thy head, because thou canst not make one hair white or black. But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil.

Matthew 5:33-37

he righteousness of the kingdom of heaven would seem at first glance to exclude any use of the oath. Oaths are necessary because of sin. Men do not value the truth so as to speak it all the time. The promises of men are unreliable. However, God values the truth. God demands that men live up to their word, even punishing those who do not. Hence, the oath: calling upon God to bear witness to the truth of what a man says. The oath is necessary because men are unrighteous.

What has the oath, then, to do with the kingdom of heaven? Christ has spoken about the righteousness of that kingdom. He has identified Himself as the fulfillment of the law and the prophets. Should we not expect the oath to be forbidden a place in His kingdom? Are not the unrighteous so excluded from this kingdom, that its citizens can be expected to tell the truth without the oath? Might it not be demanded of the citizens that they speak the truth and perform their promises without the oath? That was the conviction of the early Anabaptists. They believed that the oath was not lawful for them to practice or honor. They were convinced that the oath was wholly unrighteous, of the devil.

Yet, the King of the kingdom here teaches that the righteousness of the kingdom of heaven does have something to do with the oath. The reason for the oath is not removed. There is still sin upon the earth. The citizens of the kingdom of heaven still have their feet upon that earth. Those citizens also must fight against sin, for they still mourn over their sin. The oath is still necessary.

Furthermore, the expectation is that the righteous children of the kingdom will use the oath in righteousness. It is the present work of the King, in this passage, to teach them (and us) the proper use of the oath. 

That proper, righteous use of the oath the Lord teaches in a certain way. He distinguishes it from the wicked use of the oath. Note carefully: the abuse of the oath does not by itself make the oath as such wicked. The abuse of the oath does not make every use of the oath wicked.


Scripture records many instances of the oath expressed by men toward other men. Scripture also gives certain laws regulating the use of the oath. Those regulations Jesus recalls saying, "It hath been said by them of old time." He then brings out of the Old Testament two different teachings.

The first is negative, "Thou shalt not forswear thyself." It is taken from 
Leviticus 19:12, "And ye shall not swear by my name falsely."

Forswearing does not refer to the mere fact of swearing, but swearing falsely. One places the oath in the service of the lie. Forswearing applies to intentions. A man who forswears himself intends not at all to perform the thing to which he has sworn. He swears by an oath to do something, but he has no intention to do it. He swears to tell the truth, fully intending to lie.

The second is positive, "But shall perform unto the Lord thine oaths." It is taken from
Numbers 30:2. "If a man vow a vow unto the Lord, or swear an oath to bind his soul with a bond; he shall not break his word, he shall do according to all that proceedeth out of his mouth."

This positive commandment requires the performance of every promise made before God by way of swearing. "Thou shalt perform unto the Lord thine oaths."


This particular swearing of oaths was instituted in the Scriptures of the Old Testament. The Lord recalls that with the words, "It hath been said by them of old time." It applies very specifically to the name and the glory of God. Properly understood and used, the oath establishes the honor and glory of God far above the word of man. The oath placed a man before the glory and honor of God in his consciousness. When he swore, he declared himself liable to God's punishment, should he fail in his obligation either to tell the truth or to perform something promised. He expected God to vindicate His glory against him, should he be swearing falsely.


Jesus Christ does not merely recall these teachings of the Old Testament Scripture. In addition to what was said by them of old time, He speaks to the citizens of the kingdom an additional word. This additional word does not deny either of these things as true. He came not to destroy but to fulfill. In order to show His work of fulfilling, He brings that law to bear in a different direction.

This new direction is now necessary because of a different abuse of the oath. Wickedness sought its entrance merely by following the letter of the law and rejecting its spirit. When men swore an oath using the name of God, the obligation was acknowledged. When God's name was taken upon the lips, the oath-taker must not forswear, but must perform his word. However, when God's name was not taken in that oath, one was free of his obligations. As a result, he might name all kinds of impressive things in his oath. The time came to fulfill the obligation. The word spoken under oath was discovered to be a lie. Yet, this false-swearer was free of obligation and punishment, for he had not sworn by the name of God.

Thus, the oath lost its force and power. An oath was used no longer to put one before the face of God, for the vindication of His glory. Oaths were no longer made in order to keep God in mind. In fact, the oath was made with another purpose in mind. That purpose was in opposition to the honor and glory of God. The oath was therefore used not to perform the thing promised. It was used in the service of a lie. It was used in the service of vanity. Promises were made in order to be broken! The form of the oath was maintained, in order to gain the trust of its beneficiary. But its substance was altered—heaven, earth, Jerusalem—to release the swearer from obligation. He had no intention of performing his word.

What an awful matter! The oath had been regulated by the law of God. By its proper use God's name and glory would be upheld when the vows sworn were performed. Now, just the opposite happened. God's glory was despised. Having a creature substituted for God in the oath brought honor and glory to that creature, and not to God. The breaking of even the oaths in which God was not named would have an effect upon the oaths in which God was named. They, too, would be seen as vain. Men were to show the glory of God in their relationships with one another. They were to show the faithfulness of God. Breaking their word to one another, men also had something to say about the word of God.


Jesus' prohibition regarding these oaths must be understood with that despicable act of men in view. That prohibition is not so broad as to exclude every oath. It would be rather easy for us to draw that conclusion. After all, He said, "Swear not at all." He also said, at the end of this passage, "But let your communication be Yea, yea; Nay, nay." Further, "whatsoever is more than these cometh of evil." We could say that any and every oath cometh of evil.

There is another line of thinking, too. Since the oath was so greatly misused, so the thinking goes, it is better not to use it at all. And, if we are very careful, we might possibly avoid having ever to swear an oath.

Even so, there are difficulties with this view. So grave are these difficulties that they cannot allow such an interpretation. Though they cannot have any weight in a proper interpretation of this passage, we acknowledge several difficulties of a practical nature. An earthly judge must often require oaths of persons. Law-enforcement personnel and those occupying high office must formally swear an oath before entering into the authority and duties of that office. A soldier must swear an oath to defend the constitution of the United States before he is allowed to take his place in the armed services. The above interpretation of Jesus' words would bar any Christian from these positions. In the courts, he who refuses to swear an oath required by his magistrate risks contempt of court. Such was a reason why the Anabaptists
could not be trusted by their lawful magistrates; they refused to take oaths.

There are, more importantly, also theological difficulties. God Himself is revealed in Scripture to have sworn an oath, (
Gen. 22:16Heb. 6:13). The angel of Revelation 10, understood to be Christ, swears an oath "by him that liveth for ever and ever ..." (v. 6). The inspired language of II Corinthians 1:23 is in the form of an oath. Because of these Scriptures, and the unity of all Scripture, we must conclude that with His words our Lord does not prohibit any and all oaths.

Closer still is the word of our text. Jesus had drawn out of the Old Testament Scriptures the teaching He quoted. It is impossible that He should now contradict them. Should He do so, He would be in violation of the word that He had just spoken: "I came not to destroy but to fulfill." Were Christ here to prohibit all oaths and all swearing, we would have to conclude that He came in order to destroy the law.

Therefore, these words of Christ are a prohibition of a limited sort. The word "not at all" is further defined by the words that follow: heaven, earth, Jerusalem, one's head. Thus, "Swear not at all by these things." He forbids any and all swearing by heaven, earth, Jerusalem, or one's own head. The same thing is true of the words that end this text, verse 37. Where one would otherwise swear by these things, his communication must be simply yea or nay.

Yet, we must broaden out beyond merely this specific set of words. Of the same evil that has brought Christ to say, "But I say unto you," we must also beware. We must draw the conclusion that all oaths are forbidden that invoke the creature rather than the Creator.


Christ also gives the reason for this specific prohibition: "Whatsoever is more than these cometh of evil." This swearing of these specific oaths, in distinction from oaths in general, comes out of evil. We have seen the evil of one's intentions. He has the intention of speaking falsehood. He has the intention of reneging on his promise to do something. He hypocritically hides that intention with an oath. Merely to avoid the judgment of God, he swears by another than God. His oath cometh of evil.

The main evil of such swearing is that it denies God the glory that is due to Him. Such is the truth that Christ speaks in this passage. Swearing by these created things promotes the lie that they are wholly separated from God. The men who forswear themselves by them depend on a lie to evade the judgment of God. Their evasion is false. They still fall under judgment.

That judgment remains because they still involve God with these oaths, though not by name. Those very creatures by which men swear bear a distinct relationship to God. They may not be substituted for God in the oath, for they are His creatures. That relationship Jesus makes clear in the words before us. As Christ mentions the specific things by which men swore their oaths, He places them in relationship to God. Heaven is God's throne. Earth is His footstool. Jerusalem is His city. He makes one hair white and another one black. His is the power and the glory, even by means of those things that men wrongfully swear by.


This false, evil swearing we must see in relationship to the rest of these teachings by the King of the kingdom. He not only exercises His prerogative to rule and properly interpret the law of God. He also is the righteousness to which that law speaks. In Him, therefore, is the end of the law for righteousness, even in such matters as the swearing of oaths.

The swearing of oaths has to do, most of all, with fidelity and truth. Where men are fickle, and where men are liars, God is true. What He has spoken and what He has sworn He will certainly perform. Whereas it is in the nature of men, by sin, to violate their oaths, it is in the nature of God to do exactly as He has promised. The same thing is true of the King of the kingdom. His Word He performs. Those whom He has come to save, He will save to the uttermost. Those whom He has intended to save He saves to the uttermost—every last one.

The proper use of the oath, within the definite limits described by Christ, serves this exalted purpose. It calls attention to God's faithfulness: He alone will and will certainly punish those who swear falsely. He does this because He vindicates His faithfulness against all infidelity. In this way, God's word is sure to all those that trust in Him. What He has sworn to them—to save them to the uttermost—He will certainly perform. Their proper use of the oath, by grace, is a reflection of God's sovereign grace.


Christ also saves His people into that proper, righteous use of the oath. His righteousness completely covers the sins of His people, those given Him by the Father. Their lies, their broken oaths and hypocrisies, He covers with His blood. He pours into them His Holy Spirit, renewing them after His image. As a result, they love the truth and pursue it. They can be relied upon to speak it, even without an oath. Their promises they keep, even though they need not swear to perform it. In this, they show themselves to be citizens of the kingdom.

Questions for Meditation and Further Study:

1.What was the significance of the form used to place one under oath, "Give God the glory," as found in Joshua 7:19and John 9:24?

2.How can we understand better 
James 5:12 in the light ofMatthew 5:33-37? What is the falling into condemnation spoken of there?

3.Why would the difference between the Reformed and the Anabaptist over the oath during the Protestant Reformation be so significant? Confer Article 36 of the Belgic Confession and Lord's Day 37 of the Heidelberg Catechism.

4.Why is the oath still used in a society that so diligently strives to be secular?