YOU’VE SEEN IT in movies; maybe you’ve even seen it in an actual courtroom. A witness is called to the stand to give his or her “sworn testimony.” In other words, before they are asked to tell what they know about the case that is before the court, they are first asked to raise their right hand and swear an oath to “tell the truth, the whole truth, and nothing but the truth.” They may even be asked to take the oath in God’s name with one hand resting on the Bible.

These days, of course, there are alternatives for people who don’t believe in God and couldn’t care less about the Bible. But witnesses are still asked to make some solemn promise to tell the truth, often while being reminded of the penalty for perjury.

Do such oaths make any difference in truth-telling? Frankly, I doubt it. I’m reminded of my first summer job out of high school, working for City Hall in my hometown. As part of the hiring process, I was required to sign a document in which I literally promised not to overthrow the government. Even as a teenager, I found that rather odd. Silently, I wondered, What does that even mean? If I were planning a coup, would they really expect me to answer that question honestly? Or maybe somebody would hope I’d abandon all my dastardly plans, saying, “Darn, they made me promise.” Imagine trying to explain that to your co-conspirators: “Yeah, but guys, you don’t understand. I had to sign a form.”

I don’t know if taking an oath actually makes a person more truthful. But such customs exist because we need the truth from people, but live in a world in which we don’t trust them to speak it. Or, turning it around, we make oaths ourselves to try to convince others that we can be trusted — usually because we want something from them. “I swear on a stack of bibles!” we plead. Well, all right then, the other person is supposed to think, if it’s a whole stack of bibles I guess you really mean it!

In some ways, I guess, things haven’t changed all that much since the Sermon on the Mount.

AS WE’VE SEEN in Matthew 5, Jesus repeatedly puts antitheses in front of his hearers, contrasting what they’ve been taught about righteousness by the scribes and Pharisees with the true righteousness of the kingdom of heaven. So far, he’s addressed laws related to murder, adultery, and divorce, confronting his hearers with the deeper matters of anger, lust, covetousness, and hardness of heart. He then turns to the matter of taking oaths:

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.” (Matt 5:33, NIV)

Note that there’s nothing in particular wrong with the old teaching, as far as it goes. Moses himself, for example, had taught the people, “When a man makes a vow to the LORD or takes an oath to obligate himself by a pledge, he must not break his word but must do everything he said” (Num 30:2). It is right and good that anyone who makes a vow should keep it.

The question, however, is the heart and intent behind the oath. Imagine a scenario in which you have loaned a significant amount of money to a friend. Because you’re a Christian, you want to be generous and patient, but you really need the money to be repaid as promised. You’ve tried nicely to collect the debt, but your friend has repeatedly put you off, making one excuse after another. In exasperation, you insist, reminding your friend of their string of broken promises. In response, your friend declares, “As God is my witness, I promise to pay you back!”

How do you take that? Do you believe them and back off again? Or do you suspect — probably justifiably! — that this is just another delay tactic, dressed in false piety?

Again, in his earlier teaching, Jesus has already referred to two of the Ten Commandments: the prohibitions against murder and adultery. What he says here may be a reference to yet another of the commandments: “You shall not misuse the name of the LORD your God, for the LORD will not hold anyone guiltless who misuses his name” (Exod 20:7).

Today, unfortunately, we violate the commandment all the time, using the names “God” and “Jesus” in careless and disrespectful ways. This is not, however, just a modern problem. It had its own form in Jesus’ day. We can see this in the way Jesus accused the Pharisees of hypocrisy and moral blindness later in Matthew’s gospel:

Woe to you, blind guides! You say, “If anyone swears by the temple, it means nothing; but anyone who swears by the gold of the temple is bound by that oath.” You blind fools! Which is greater: the gold, or the temple that makes the gold sacred? You also say, “If anyone swears by the altar, it means nothing; but anyone who swears by the gift on the altar is bound by that oath.” You blind men! Which is greater: the gift, or the altar that makes the gift sacred? Therefore, anyone who swears by the altar swears by it and by everything on it. And anyone who swears by the temple swears by it and by the one who dwells in it. And anyone who swears by heaven swears by God’s throne and by the one who sits on it. (Matt 23:16-22)

The Pharisaic version of legalistic righteousness, in other words, had nothing to do with the honesty or sincerity of the oath; the focus was rather on whether one used the right words, the right formula. Don’t swear by the temple, swear by the gold in the temple. Don’t swear by the altar, swear by the offering on the altar. And so on. One can easily imagine the twisted and self-serving ways in which people could avoid taking responsibility for the vows they made on such purely technical grounds.

Jesus’ point in this passage seems to be that whichever formula one uses, all of it is in essence swearing by God. You don’t have to invoke God’s name directly. And that, in turn, meant that if you didn’t keep your vow, you couldn’t claim to be innocent of misusing God’s name just because you swore by the temple instead.

Jesus taught the same lesson in the Sermon on the Mount. But this wasn’t just a game of linguistic rules for valid and invalid oaths. The Pharisees had missed the point. Kingdom righteousness has more to do with the kind of character we embody in relationship to others. And the issue, as we’ll see next, is this: can we trust each other to mean what we say?