Must we always keep our vows/oaths to God? Is it better to break an oath or fulfill an unwise or sinful vow?

from the old testament

• Vows in the Old Testament were treated as solemn and binding commitments made before God. Numbers 30:2 says, “If a man vows a vow to the LORD, or swears an oath to bind himself by a pledge, he shall not break his word. He shall do according to all that has proceeded out of his mouth.” Likewise, Deuteronomy 23:21–23 commands that once a vow is made, it must be fulfilled because the promise is given directly to God. This shows the seriousness of keeping one’s word.
• At the same time, Scripture warns that words made hastily bring guilt. Leviticus 5:4–5 indicates that making a rash vow requires repentance to God. In Mosaic Law, that took the form of a female lamb or goat.Thus, though vows are serious, when the vow itself is sinful, acknowledging guilt, and bringing an offering was required (Leviticus 5:6).
• Proverbs also warned against speaking too quickly before God. “It is a snare to say rashly, ‘It is holy,’ and to reflect only after making vows” (Proverbs 20:25). This verse links foolish promises with entrapment—what seemed pious at first becomes a burden that leads to guilt. The wise, therefore, measure their words before the LORD and repent rather than stubbornly following through on a sinful commitment.
• Jephthah’s story in Judges 11 illustrates the tragedy of rash vows. Before battle, he promised God, “If you will give the Ammonites into my hand, then whatever comes out from the doors of my house to meet me when I return in peace from the Ammonites shall be the LORD’s, and I will offer it up for a burnt offering” (Judges 11:30–31). While he was likely expecting an animal, when his daughter was the first to greet him, he kept his vow and may have killed her instead of confessing his foolishness. (Some say the fact that his daughter took time to “weep for [her] . . . virginity” in Judges 11:37 suggests that she went to temple service rather than marrying. This interpretation is supported by practices in Exodus 13:1-2, 11-16 and by the passage in which Hannah promises Samuel to God and gives Samuel to temple service in 1 Samuel 1). The account highlights the danger of thinking that pleasing God requires fulfilling a sinful vow rather than repenting of it.
• Saul’s rash oath in 1 Samuel 14 is another example: “Saul had laid an oath on the people, saying, ‘Cursed be the man who eats food until it is evening and I am avenged on my enemies.’ So none of the people had tasted food” (1 Samuel 14:24). His vow nearly cost his son Jonathan’s life who didn’t hear the command and ate something, as well as weakened the army in battle.

from the new testament

• Jesus taught that His followers should not need to make vows at all. In the Sermon on the Mount, He said, “Do not take an oath at all, either by heaven, for it is the throne of God, or by the earth, for it is his footstool, or by Jerusalem, for it is the city of the great King. And do not take an oath by your head, for you cannot make one hair white or black. Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil” (Matthew 5:34–37). His command was not a rejection of all solemn promises—Scripture records God Himself making oaths—but a warning against the type of careless or manipulative speech common during His day. Disciples of Christ are to speak truthfully at all times so that their word stands on its own.
• James echoed this instruction to the church: “But above all, my brothers, do not swear, either by heaven or by earth or by any other oath, but let your ‘yes’ be yes and your ‘no’ be no, so that you may not fall under condemnation” (James 5:12). His warning reinforces that honesty and simplicity in speech mark genuine faith.

implications for today

Making a vow is not sinful in itself. A vow is simply a promise—to God or to another person—and as followers of Christ, our words should carry the weight of truth. Because God is faithful and never lies, His people should be known for keeping their word and following through on their promises. Whether spoken publicly or privately, every commitment we make should be done thoughtfully and fulfilled diligently, as an expression of integrity that honors the Lord.

Yet sometimes we make promises that cannot be kept or that would require disobedience to God to fulfill. In those moments, when we realize we have spoken foolishly, we need to confess our sin to God and seek forgiveness from the one we wronged (1 John 1:9). It is better to humble ourselves and admit our failure than to increase our guilt by sinning to keep our word.

Every vow, every promise, and every word we speak reflects something about the God we serve. He never lies, never breaks His word, and never acts unjustly. Our goal is to mirror that faithfulness in how we live and speak.