What Jesus says about oaths and honesty

According to Carson, in the third block of text, Jesus addresses the issue of honesty. The people had heard what had been said long ago: “Do not break your vow, but keep the oaths you have made to the Lord” (5:33).

This is not a direct quote from the Old Testament, but an allusion to passages such as Exodus 20:7, Leviticus 19:12, Numbers 30:2, and Deuteronomy 23:21-24. However, Jesus now says, “Do not swear at all” (5:34).

Some think this prohibits them from taking an oath in court or taking an oath of allegiance. These people's desire to obey God's Word is admirable, but I have to admit they misunderstand it.

As always, Jesus is preaching by antithesis, and it is important to find out exactly what he is saying before we take his statement with such callous abandon.

The Old Testament

First of all, it should be noted that the Old Testament allows men to make oaths, even in the name of God: “Fear the Lord your God and serve him. Hold fast to him and swear by his name alone” (Deuteronomy 10:20).

Even in the New Testament, Paul, for example, frequently swears by God's name. He even calls God as his witness (Rom. 1:9; 2 Cor. 1:23; 1 Thess. 2:5, 10; cf. Phil. 1:8). So if Paul knew of this teaching of Jesus, he certainly did not interpret it absolutely.

God himself swears: he swears not to send another universal flood (Gen. 9:9-11), he swears to send a redeemer (Luke 1:68, 73), he swears to raise his Son from the dead (Ps. 16:10; Acts 2:27-31), and much more.

All these vows and oaths are intended to encourage honesty or to make it even more solemn and assured.

Sometimes it's even spelled out for us

In one case, for example, we read: “For God, wanting to clearly show the unchangeable nature of his purpose to the heirs of promise, confirmed it with an oath” (Heb. 6:17).

For the same reason, the Mosaic code prohibited only false or irreverent oaths, which must be considered a profanation of God's name.

Unfortunately, however, by the time of Jesus, the Jews had built an entire legalistic system around the teachings of the Old Testament.

The Jewish legal code, the Mishnah, contains an entire tractate devoted to the issue of oaths, including a detailed analysis of when they are binding and when they are not.

For example, a rabbi says that if someone swears by Jerusalem, he is not bound by his vow; but if he swears in the direction of Jerusalem, he is bound to fulfill his vow.

Thus, oaths degenerate into a series of terrible rules that tell you when it is possible to use lies and falsehood with impunity and when it is not.

These oaths no longer encourage honesty, but rather weaken the cause of truth and promote deception. Swearing evasively becomes an excuse for lying.

Jesus does not allow this kind of sophistry among his followers.

If men want to play this game with vows, it simply destroys any and all vows. Jesus is interested in honesty, its constancy, and its unconditionality.

Jesus gives examples. Men should not swear by heaven or earth, for these are respectively God's throne and his footstool.

People should also not swear facing Jerusalem (if we translate the preposition literally), because it is the city of God, the great King.

One should not swear by one's own head (cf. 1 Sam. 1:26; Ps. 15:4), for one cannot change the color of even a hair on one's head: that is, one is swearing by something over which only God has complete control.

In other words, Jesus associates every vow with God.

To swear by anything is to swear by God, for He is behind everything. Therefore, no oath is trivial, no oath is a justifiable evasion; every oath is a solemn promise to speak the truth. Jesus expands on this point in another passage:

Woe to you, blind guides! You say, “If anyone swears by the temple, it is nothing; but if anyone swears by the gold of the temple, he is bound by his oath.” You blind and foolish people!

Which is greater: the gold or the temple that sanctifies the gold?

You also say, “If anyone swears by the altar, it is of no consequence; but if anyone swears by the gift on it, he is bound by his oath.”

You blind men! Which is greater, the gift, or the altar that sanctifies the gift? Therefore, whoever swears by the altar swears by it and by everything on it.

Whoever swears by the temple swears by it and by Him who dwells in it; and whoever swears by heaven swears by the throne of God and by Him who sits on it (Matthew 23:16-22).

The real issue here is honesty. For a follower of Jesus, it's better to simply say "yes" or "no" with sincerity.

In the context of Jesus' time, anything beyond this comes from the Evil One (5:37), who is quite appropriately called the father of lies (John 8:44).

Jesus' teaching on honesty made a deep impression on the early church, for in what was perhaps the first epistle of the New Testament, the Epistle of James, the same point is emphasized (James 5:12).

Final Words

Christians claim to have the truth and to follow the one who is the Truth (John 14:6). In our conversations, therefore, truth should be our motto.

How many of us embellish our stories a little in a reprehensible way, either to reinforce our argument or to appear more interesting to others than the actual facts would allow?

How many of us say we're going to do something and then go back on our word because keeping our promise causes us some inconvenience?

You, who, like me, are teachers and preachers, how often do you also fabricate evidence to demonstrate a point of view or speak categorically about subjects you know nothing about, hoping that your dogmatic stance will hide your own ignorance?

I'm not talking about an honest mistake, but about fraud. Our Lord insists that Old Testament Scripture points to honesty, and all who submit to his authority must speak only the truth.

To learn more about this topic, read our next article, “The Sermon on the Mount, Within Reach of All.” I recommend that you study Carson’s book, “The Sermon on the Mount,” which inspired this article.