Sacred Oaths and Vows
"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 proceeds out of his mouth" (v. 2).
Continuing our look at the third commandment, we come now to the topic of oaths and vows. Since oaths and vows are sworn in the name of God, they fall under the right application of what it means not to take His name in vain (Deut. 5:11). Question and answer 101 of the Heidelberg Catechism begin its summary of the biblical teaching on vows, showing us how to take sacred oaths in the Lord's name.
Some Christians believe that God now forbids oaths. This is due to a few New Testament passages that seem to bar us from making vows (Matt. 5:33–37; James 5:12). We will discuss these texts in more detail tomorrow, but today we note that sacred oaths and vows are a common part of biblical religion. Abraham, for example, swore an oath when he made a covenant with Abimelech (Gen. 21:22–34). King Asa and the people of Judah vowed to seek the Lord in their reformation of worship (2 Chron. 15:1–15). Even God Himself swore to Abraham that He would keep His covenant promises (Heb. 6:13–20). Since our holy Creator made a vow, oaths cannot be sinful in and of themselves.
But why do human beings even need to make oaths and vows? It is because of sin. Scripture says that "all mankind are liars" (Ps. 116:11), not because people tell nothing except lies but because we are all prone to twist the truth and to look for wiggle room when it comes time to fulfill our promises. Thus, we swear oaths to assure others of our trustworthiness. In taking an oath or vow in God's name, we are saying that our word is so truthful that we are willing to suffer the judgment of the Lord if we break it. Even if no man sees us break our word, God will, and He will hold us accountable. Oaths are tangible signs by which we guarantee the authenticity of our promises. On a divine level, however, God swears oaths not because He is untrustworthy; rather, He swears oaths as a condescension to us, to give us help in trusting His promises.
As with other ethical matters the Bible addresses, the key aspect of an oath is the intent of the heart behind it. Oaths and vows in themselves do not establish truth. They testify to the swearer's intent to keep a promise. An oath only has value in upholding the truth of what is promised if the one who makes the oath intends to fulfill it. If a vow is broken, that which was sworn is shown to be false; however, the truth that God will hold accountable those who violate sacred vows remains (Num. 30:1–2).
Coram Deo
This quote from William Shakespeare All's Well That Ends Well captures an important insight: "'Tis not the many oaths that makes the truth, but the plain single vow that is vow'd true." Sacred vows are not to be taken carelessly, but much deliberation should be put into the matter before an oath is made. A true intent to keep the vow must be present, otherwise we sin when we make an oath in the name of God.