WCF 22: Of Lawful Oaths and Vows

The question of the propriety of vows and oaths may not strike us as an urgent matter. All serious religious questions are important but vows and oaths may seem like less weighty matters of the law. Actually, this topic helps us get to the very nature of truth itself and what it means to follow God with integrity. In fact “religious oaths” and vows are “part of the ordinary religious worship of God” (21:5). We honor God by using his name in making worthy commitments.

Oaths and vows are two similar ways of showing our commitment to truth. An oath is a promise to another person in the name of God and in consciousness of his holy presence. A vow is a promise made directly to God. Vows are typically voluntarily (Deut. 23:21–23) while oaths may be “imposed by lawful authority” (Neh. 5:12). So vows and oaths are different but have enough in common to be studied together as ways we can solemnize our commitment to the truth.

The Validity of Vows and Oaths

Vows and oaths call God to witness to our assertions of truth or our pledges of action.  They can be made “upon just occasions” in “matters of weight and moment” to establish our credibility or reinforce our commitments.

Sadly sacred promises testify to the radical untrustworthiness of humanity. We should always uphold the truth. But men are liars (Rom. 3:4). So in especially weighty matters it may be necessary to invoke God’s name to prove our sincerity and deepen our commitment to fulfill God’s holy will. Hebrews six explains how this works: “For people swear by something greater than themselves, and in all their disputes an oath is final for confirmation” (16). Of course, the value of an oath depends on one’s belief that God actually witnesses the promise and truly holds the swearer responsible. Only a person who disbelieved in God and in his fierce commitment to the truth would make a vow he didn’t intend to keep. Because God’s name is great we must not use it falsely or in light matters.

Still, Scripture commends proper vows. When Israel was about to enter the Promised Land Moses reminded them of God’s faithfulness and their duty to fear him, walk in his ways, and serve him with heart and soul. As part of their devotion the people were also to swear by his name (Deut. 10:12, 20). God was to be at the heart of their deepest commitments. If they were called upon to testify in a trial, God was present in judging their answers. If they entered into a business partnership, or got married, they should recognize that God was like the third strand that can bind together two human parties (Eccl. 4:12). In the New Testament the apostle Paul placed himself under oath to try to convince the Corinthians of his pure motives. Some had complained that he had wronged them in writing to them rather than visiting them face to face. So Paul swore: “I call God to witness against me—it was to spare you that I refrained from coming again to Corinth” (2 Cor. 1:23). And Jesus himself took an oath. “The high priest said to him, ‘I adjure you by the living God, tell us if you are the Christ the Son of God’” (Matt. 26:63). Jesus, under oath, answered him.

We make sacred pledges when we sign legal contracts, enter into covenants like marriage, make oaths as civil servants or courtroom witnesses, or take vows to raise our baptized children in the fear of God, maintain our profession of faith, or fulfill our duties as church officers, among other possible examples.

The Way to Make Vows and Oaths

Here are three critical steps toward making a proper vow or oath.

Prove the Validity of the Pledge

Should the vow be made? Is the promise “good and just?” Are you fully convinced in your mind (Rom. 14:23)? Do you believe yourself capable, God helping you, to perform the vow? Could the vow you are consider invoke God’s name with “holy fear and reverence”? Rash vows are foolish because they bypass the evaluation process. Vows made in desperation, anger, a sense of self-importance, or a perverted view of justice do not honor God (see Judges 11; see 1 Samuel 25; Acts 23:14). “Consider the weightiness of so solemn an act” as to call God as your witness.

Phrase Your Promise Accurately

Be honest. Use the right words. Avoid equivocation. Don’t give the impression of truth while hiding other intentions.

And then call on God alone as witness. Because only God can actually hold us to our vows, we may not swear by heaven or earth or anything else (Matt. 5:34, 37; James 5:12). Swearing in the name of ordinary objects or beings conveys the exact opposite of the intent of a biblical oath. Swearing on your mother’s grave may sound dramatic. But the grave of your deceased mother has no way of holding you accountable to your vow. Such expressions are swearing in the wrong sense of the world; they amount to bravado, a rant by one whose words cannot stand on face value.

Plan to Follow Through

A vow “binds to performance.” You must keep your vows even when they hurt (Ps. 15:4), even when others do not share your values. Many people break their vows when keeping them gets hard—this is just when promises are needed most! Divorce is common today not because marriage has gotten harder but because people increasingly lack the willingness to persevere.

Of course, some vows should be broken. King Herod vowed to give his step-daughter anything she wanted. That was sinful as the vow had inadequate boundaries. He was horrified by her request of John the Baptist’s head on a platter. “But because of his oaths and his guests he did not want to break his word to her” (Mark 6:14–29). We should never follow-through on an oath that makes us sin.

The big point of this lesson shouldn’t be lost in the detailed instructions. You and I must make important commitments and trust Christ to help us fulfill them. Some commitments are absolutely essential. We must each vow loyalty to Jesus and to his body the church. We cannot remain undecided. The entire life of faith is not about following our feelings or being ruled by circumstances but about making and keeping commitments. We should make the same vow as the Israelites when they prepared to enter the land of Canaan, “The Lord our God we will serve, and his voice we will obey” (Josh. 24:24).

And we can make this vow, and aim to keep all of the resulting responsibilities knowing that we have on our side the one who vowed to rescue us from sin and bring us to heaven. God guaranteed with an oath his promise to save sinners (Heb. 6:17–18). The God who promised to bless Abraham and his seed has sent Jesus—from heaven, to earth, to the cross, to the grave, and to the right hand of God—as proof. God can be trusted. If we devotedly follow him we will never regret it.

William Boekestein pastors Immanuel Fellowship Church in Kalamazoo, Michigan. He has authored numerous books including, with Joel Beeke, Contending for the Faith: The Story of The Westminster Assembly.

William Boekestein