I remember the day took my military oath with a group of others that included another Airman, a couple of soldiers, and a seaman. The young lieutenant who took our oaths was very serious and somber. We could feel the gravity of what we were doing. She made us raise our right hand a repeat after her. I remember vividly the part of the oath where she said, "I solemnly swear or affirm to..." Having a Christian background, I full understood why the oath was worded in this way.
I remember the conversations about swearing in Bible classes and in casual conversation among Christians growing up. Jesus taught us not to swear, but to let our yes be yes and our no be no (Mt 5:33ff). According to some of the older Christians there, the reason for this was because you would be irrevocably tied to an oath, which would not be good. What if you took an oath and for some reason you didn't keep it? This would be sin. Therefore, they reasoned, it was better not to take an oath and just let your yes be yes and your no be no. Instead of taking oaths, you could "affirm" your word like they allowed you to do at the swearing in ceremony for military service.
At the time, I wondered if affirming your word was really a whole lot different than making an oath. Didn't they function in pretty much the same way? Just like everyone else, those who "affirmed" their commitment to the military held up their right hand and said the same words with the exception of the word, "swear." Looking back, I have to wonder if this didn't miss the point of Jesus' teaching altogether? Should a simple yes or an affirmation be any less valid than an oath? Does the only trustworthy word come in the form of an oath? Is it acceptable if you break your "affirmation" but not your "oath?" Wouldn't this basically be lying? What if God operated in this way and kept his word only if it came in the form of an oath?
We know that God always keeps his word because he is faithful (Ps 100:5) and does not lie (Heb 6:18). He is the God of truth (Dt 32:4; Jn 14:6) and there is no falsehood in him (1 Pet 2:22). It is the Devil, not God, who is a liar and the father of all lies (Jn 8:44). When the Devil lies, it comes from his very nature as a liar. However, the nature of God is faithfulness and truth (Ex 34:6; Dt 7:9). If we who are created in the image of God are to reflect the nature of our creator, we will be lovers of truth. Our word will be trustworthy and full of integrity. We will not look for loopholes that will allows us to weasel out of a simple promise or commitment. We will only use oaths in the same way that God did (Gen 22:16), which would not be flippant every day occurrences, but special occasions. This would not be for our benefit to bind us, but for the benefit of those who do not yet know our godly character and need extra reassurance in our word (Heb 6:16-17).