Can I Take an Oath?

Matthew 5:34-35 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.

James 5:12 Above all, my brothers and sisters, do not swear - not by heaven or by earth or by anything else. All you need to say is a simple "Yes" or "No." Otherwise you will be condemned.

Hebrews 6:13, 17 When God made his promise to Abraham, since there was no one greater for him to swear by, he swore by himself.... Because God wanted to make the unchanging nature of his purpose very clear to the heirs of what was promised, he confirmed it with an oath.

Revelation 10:5-6 Then the angel I had seen standing on the sea and on the land raised his right hand to heaven. And he swore by him who lives for ever and ever, who created the heavens and all that is in them, the earth and all that is in it, and the sea and all that is in it, and said, "There will be no more delay!"

There is a simple explanation to this. There are good oaths consistent with God's character and bad oaths. Christians should not take bad oaths, such as those which are false, encompass evil, and are vain or frivolous. Of course, one may do those which are sacred, true, and good (Gen. 21:24; Deut. 6:13). Jesus himself submitted to being put under oath by the high priest at his trial (Matt. 26:63). Paul invoked God as his witness (Rom. 1:9; cf. 2 Cor. 1:23; 1 Thess. 2:10). Godly vows are not prohibited because they form a vital part of all covenants.

In Matthew 5, Jesus was addressing the problem of casuistry (the use of ethical principles to resolve moral problems) that required a specific oath to make the spoken words binding. The implication of such a methodology is that when one does not take an oath, they cannot be trusted. Jesus was simply saying that when a Christian speaks it should always be truthful - as if an oath was present (WCF 21.5; 22:2, etc.). The Christian norm is their word can ALWAYS be trusted.

As the Westminster Confession of Faith teaches:

Chapter XXII

Of Lawful Oaths and Vows

I. A lawful oath is part of religious worship, wherein, upon just occasion, the person swearing solemnly calls God to witness what he asserts, or promises, and to judge him according to the truth or falsehood of what he swears.

II. The name of God only is that by which men ought to swear, and therein it is to be used with all holy fear and reverence. Therefore, to swear vainly, or rashly, by that glorious and dreadful Name; or, to swear at all by any other thing, is sinful, and to be abhorred. Yet, as in matters of weight and moment, an oath is warranted by the Word of God, under the New Testament as well as under the old; so a lawful oath, being imposed by lawful authority, in such matters, ought to be taken.

III. Whosoever takes an oath ought duly to consider the weightiness of so solemn an act, and therein to avouch nothing but what he is fully persuaded is the truth: neither may any man bind himself by oath to any thing but what is good and just, and what he believes so to be, and what he is able and resolved to perform. Yet it is a sin to refuse an oath touching any thing that is good and just, being imposed by lawful authority.

IV. An oath is to be taken in the plain and common sense of the words, without equivocation, or mental reservation. It cannot oblige to sin; but in any thing not sinful, being taken, it binds to performance, although to a man's own hurt. Not is it to be violated, although made to heretics, or infidels.

V. A vow is of the like nature with a promissory oath, and ought to be made with the like religious care, and to be performed with the like faithfulness.

Yes, Christians can take oaths, but they are serious business (Jephthah and Sinful Vows). However, whether an oath is present or not - "the norm" is a Christian is expected to be one of noble character, telling the truth.

Related Answer:

Disobeying Government Authority - Exodus 1:15-21