Again, you have heard that it was said to the people long ago, ‘Do not break your oath, but fulfill to the Lord the vows you have made.’ But I tell you, do not swear an oath at all: either by heaven, for it is God’s throne; or by the earth, for it is his footstool; or by Jerusalem, for it is the city of the Great King. And do not swear by your head, for you cannot make even one hair white or black. All you need to say is simply ‘Yes’ or ‘No’; anything beyond this comes from the evil one. (Matthew 5)
In the Harry Potter novels, the Marauder’s Map is accessed by the use of the passphrase “I solemnly swear that I am up to no good”. Rowling intended this to be a bit ironic, because generally her characters used the map for good, although possibly rule-breaking, purposes. In this passage from the Sermon on the Mount, Jesus elaborates on the commandment “Thou shalt not use the name of the Lord thy God in vain”. Jesus goes beyond the rule to the principles of honesty and loyalty that underpin it. Don’t promise something you have no intention of delivering, or can’t deliver.
When I was a child, I thought the Third Commandment referred to “cussing”, meaning using “bad words”, some of which strangely enough had more to do with bodily functions than with God. Adhering to that understanding of one of the Big Ten might have kept me out of trouble with parents and teachers, but that’s not at all how I understand that commandment now. Most modern translations of the Hebrew words phrase it “you shall not misuse the name of God”, and there are many passages in the Old Testament which give examples of the proper and improper use of oath-taking. Using God’s name to promise something was a kind of unbreakable vow, at least for men; a woman’s vow could be overruled by her father or husband. Whatever you promised in God’s name had to be done, even if it turned out to be a rash statement, as Jephthah learned to his sorrow. A modern parallel might be the courtroom custom of placing one’s hand on the Bible and swearing to “tell the truth, the whole truth, and nothing but the truth, so help me God.”
The problem with attempting to regulate moral behavior with rules instead of principles is that it does not always work. People look for and find loopholes or twist the intended purpose of the law in order to benefit themselves, and that does not make God happy. In Matthew 23, Jesus gives one example of such behavior in his time, coupled with a strong warning that it is highly displeasing to God. “Woe to you, scribes and Pharisees, you hypocrites! You traverse land and sea to win a single convert, and when he becomes one, you make him twice as much a son of hell as you are. Woe to you, blind guides! You say, ‘If anyone swears by the temple, it means nothing; but if anyone swears by the gold of the temple, he is bound by his oath.’ You blind fools! Which is greater: the gold, or the temple that makes it sacred?” Today anyone who keeps up with the news is painfully aware of how often political figures distort the truth to serve their own purposes, make empty promises, and/or dance around the edges of perjury. And don’t get me started on people who claim that God wants you to send them money, or that God told them to run for political office, or that God told them to commit acts of violence and hate in his name. I think God gets especially mad when people use his name to say and do things that drive people away from God. As Paul put it, “God’s name is blasphemed among the Gentiles because of you”
Using God’s name in vain is serious business, and God’s name is used in vain when it is invoked to make promises that won’t be fulfilled, or when it is used to justify human behavior that it is self-serving or harmful to others. Just leave God’s name out of it, Jesus says. Say what you mean and mean what you say. A tree will be known by its fruits, and if you regularly practice the principles of honesty, loyalty, and commitment that will be readily apparent to others as well as pleasing to God.