To understand rightly the teaching of Scripture, we must have some understanding of the original context in which it was given. This is particularly true when it comes to the biblical instruction on oaths and vows. As we have seen, passages such as Matthew 5:33–37 do not forbid oaths and vows altogether. Instead, the text is responding to a first-century error that said one could escape divine displeasure for breaking a vow if one made the vow in the name of something the Lord created rather than the name of the Lord Himself. Many first-century Jews believed God did not view oaths made by swearing according to the temple or the heavens as being as serious as oaths sworn in His name. Complex and sophisticated oral tradition had even developed regarding how the oaths were sworn to identify the degree to which oaths were breakable or unbreakable.
Not all traditions are inherently wrong; extrabiblical traditions that do not violate biblical teaching—such as the time one chooses to hold a worship service, for example—are not sinful. However, the oral traditions surrounding the swearing of oaths in the first century were not traditions of this kind. They violated Scripture in at least two ways. First, our Creator demands that we keep all lawful oaths (Num. 30:1–2). To try to give oneself an "escape clause" for breaking an oath or vow by allowing for promises not made directly in God's name to be broken denies the intent of His law.
Second, the Lord tells us that we should swear oaths only in His name, thereby forbidding us from making oaths or vows in the name of any created thing (Deut. 6:13). In an oath, we are calling upon something or someone greater than ourselves to hold us accountable to our word. We are calling upon that someone or something to ensure that we keep our vows. But this is something of which only God is capable. Nothing else in creation has the omniscience and omnipresence necessary to know perfectly when we have and have not kept our promises, and no one else has the omnipotence required to hold us perfectly accountable to our word. We can hide our violations from others, but not from the Lord. To swear an oath in the name of something created is to impute incommunicable divine attributes to that which is not deity. It is, to put it bluntly, to commit idolatry. Other people may witness our taking oaths in order to remind us that we have made a promise in God's name, but it is God Himself who will hold us finally accountable to our word.
The principle that we are not to make oaths in the name of anyone but God alone is a powerful reminder of the sanctity of God's name. When we use the Lord's name in vain, we are attributing to someone or something else the glory that He alone deserves, and that is a great sin. Worshiping God rightly entails paying close heed to how we use His name, so may we make oaths carefully and then only in His most holy name.