What does the Bible say about keeping your vows / oaths? What happens if we break a vow we made to God?

Scripture tells us to "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." (Matt. 5:34-36).

In the Old Testament many vows were made and there it was right to make them. Israel made vows under law, they said they would keep the law, "All the words which the Lord hath said will we do" (Ex.24:7), but they did not keep the law. It was all right to make the vow, God did not tell them not to do it, but not to keep it once it was made was a bad thing. This was true all through the Old Testament. Many, many times covenants were made and every time they were broken. The Old Testament teaches that man is so utterly untrustworthy that it is no use making vows. What is the sense then? Why not perform without making a vow? The Old Testament Scripture says, "Better is it that thou shouldest not vow, than that thou shouldest vow and not pay" (Eccl.5:5). This is confirmed by the Lord Jesus when He said, "Do not swear at all" and James when he said "swear not, neither by heaven, nor by the earth, nor by any other oath; but let your yea be yea, and your nay, nay, that ye do not fall under judgment" (Jas.5:12), that is, there is to be no making oaths, nor vows, rather the believer today is under the grace of God. Jacob was repeatedly told by God that He was full of kindness towards him. God did not ask him to make a vow, and he would have been far better off if he had not, but making the vow only demonstrated the fact that he could not be trusted.

If a person is very certain that he is altogether trustworthy let him make a vow then, let him go ahead and see what happens. If this serves to wake a person up to realise that he has a sinful nature and he needs Christ, he needs to trust someone outside of himself, well then, perhaps in the long term it serves a purpose.

If one made a vow to the Lord he must pay it all at the appointed time (v.21), for negligence in this was sin. How much better not to vow at all than to make a promise and not keep it! This law should have by itself kept Israel from making questionable vows. However, the Lord Jesus, in speaking of this law, says, "But I say to you, do not swear at all" (Mt.5:33-34). Man in the flesh is proven by Old Testament history to be untrustworthy, and therefore in the New Testament we are warned against making promises or even announcing what we are going to do in the future, which includes the very near future (James 4:13-16). For even though we intend to act on our promise, we may find ourselves unable to. What a contrast is seen in God's promises, He who not only promised but "confirmed it by an oath" (Heb.6:17), for His promise and His oath are absolute: they cannot be broken.

We need not question the sincerity of the people of Israel when they promised again and again amid the solemn scenes at Sinai, "All that the Lord hath said we will do and be obedient." Or again, when notwithstanding the most solemn warnings, they renewed the covenant of works in the plains of Moab. Or yet again, when put in possession of the promised inheritance, they protested to Joshua, "Nay, but we will serve the Lord." And when he added, "Ye are witnesses against yourselves that ye have chosen you the Lord to serve Him," they said, "We are witnesses" (Ex. 19, 24; Deut. 29; Joshua 24). But if we may hesitate to question their sincerity at the time, we cannot be ignorant that, with every help and incentive to obedience, they were invariably unfaithful; and this unfaithfulness to their covenanted engagements was visited, in the righteous government of God, with sore judgments, as Moses and Joshua warned them. How serious a matter it is then to make solemn promises and vows to the Lord and not fulfil them! "When thou vowest a vow unto God, defer not to pay it, for He hath no pleasure in fools" (Eccles. 5:5).

The Israelites were not told to make vows, but if they voluntarily made them, God said they must conscientiously perform them. Man is ever ready to boast of his strength, not being conscious of his own weakness. Israel, on hearing the law, did not hesitate to say, "all that the Lord hath said we will do;" but they alas, miserably failed. The law made vows binding, and gave directions as to exceptional cases where it was impossible to perform them. Num. 30:2-14; Deut. 23:21-23; Ps. 1:14; Ecc. 5:4-5; Nahum 1:15; etc.

Many of the old church fathers like Justin, Irenaeus, Origen and Jerome, understood the Lord's words, "swear not at all," to mean that a Christian ought not to take an oath under any circumstances. In addition many sects like the Quakers and Jehovah's Witnesses reject the taking of any kind of oath. It is therefore understandable that children of God repeatedly ask, "Is a Christian allowed to swear?"

If the oath only serves as confirmation of ones own words, because one fears that they are not believed, it is not allowed. As children of God, we should always speak the truth (Eph. 4:25). This should not need any additional confirmation.

213 The Lord Himself said, "Swear not at all" so we should not voluntarily take an oath, that is, of our own choice and will. But the Lord Himself when He stood before the high priest, the moment He was adjured, took the oath and answered when He had been silent before. It is not evil before a magistrate to swear, but good; it comes of evil otherwise. I should deny God in the magistrate if I did not answer when he adjured me. But to take an oath of my own will is to bring in God for nothing at all, that is, profanely. So the sin here in this verse is not uttering, that is, withholding evidence. In Exodus 21:6 (and twice in chapter 22:9, and once in chapter 22:8), "judges" is "elohim" - God, and this because the magistrate is for God: "the powers that be are ordained by God." We are to submit to them.

Mr. Jowett refers to "Swear not at all." Matt. 5:34. As this question comes often into public, I will just refer to this too. The same principle which hinders my swearing of myself, makes me take an oath, as it is called, before a magistrate. I bring in God lightly in one case; I own Him in the magistrate, as I am bound to do, in the other. The Lord and James speak only of voluntary oaths — what comes from self. Whatsoever is more than this comes of evil (i.e., more than yea, yea, and nay, nay, in our conversation). So the Lord speaks of vows, i.e., voluntary swearing to the Lord. But in Leviticus 5 we find adjuring and a man bound to utter it; and, consequently, the Lord answers before the high priest. The oath imposed by a magistrate is adjuring, and I judge a man to be wholly in fault who does not take the oath; he disowns God's authority in the magistrate.

Then another snare is connected with this for avoidance: "Above all things, my brethren, swear not, neither by heaven, neither by the earth, neither by any other oath: but let your yea be yea; and your nay, nay; lest ye fall into condemnation." What has the apostle in view here? The oath before a magistrate? In no wise does scripture slight that solemn obligation. The Lord Himself respected the adjuration of the high-priest; and in no passage whatever do we see a depreciatory allusion to a judicial oath in the sermon on the mount, or, in what James says here, or in any other part of the Bible, but the contrary. The Lord was addressing Jewish disciples, James writes to the twelve tribes of Israel who are in the dispersion; but what they both set their faces against was the habit of bringing in religious asseverations for the purpose of confirming their word every day, besides the profaning of the Lord's name in matters of this life. This in point of fact weakens instead of establishing what is said; for it is evident that whatever is uncalled for gives no strength to an assertion, but is just a fruit and proof of weakness. Where there is simple truth, nothing is needed but the quiet statement of the fact.

There were no people so prone to ordinary swearing as the Jews. Accordingly, I have not the slightest doubt that what our Lord and His servants reprobated was the introduction of an oath in common conversation; and this, it is plain, does not apply to an oath administered by a magistrate. Indeed, it seems to me in itself sinful for a man to refuse an oath (supposing its form otherwise unobjectionable) if required to do so by proper authority. It would be to me a virtual denial of God's authority in civil government here below. I believe, therefore, that it is the bounden duty of every man to whom an oath is put, to take it in the fear of the Lord. I admit it must be put by competent authority. Therefore we are not to assume that the passage in Matthew 5, or this portion of James, has the smallest reference to judicial swearing. How could one think that those who indulge in such thoughts show any real intelligence as to the word of God? They certainly exhibit a certain care for conscientiousness. This is not in the least denied. But we have to take care that we are guided of God in this, which is important in the present day when we know that the spirit of the age is endeavouring to blot out God in all that touches man here below. The Lord was silent till adjured by the high-priest: was not His conduct thus perfectly consistent with His own teaching? An oath, therefore, should not be refused when put by a magistrate. I am supposing, of course, that there is nothing in the terms of the oath that would involve false doctrine or countenance a superstition. For instance, in a Roman Catholic country there might be reference to the virgin, or angels, or saints. Such an oath I do not think that a Christian man would be at liberty to take. But I am supposing now that a person is required in the name of God to declare what he believes to be the truth in a matter of which he is a witness, the truth, the whole truth, and nothing but the truth. It appears to me that so far from his being at liberty to refuse this, he is on the contrary guilty, through ignorance, of no small sin in cavilling about the matter.

The second section of the chapter (Num. 6:9–13) deals with the case of a Nazarite’s vow being broken. On the one hand this section is very solemn, on the other hand it is immensely comforting, for we shall see that God has provided an offering especially for this case (Num. 6:10) and that He makes a fresh start possible (Num. 6:11, 12).

In His grace – which is seen again and again even in the Old Testament – God had provided an offering especially for this case of a Nazarite’s broken vow. This offering involved several animal sacrifices and various kinds of offerings: