Of Atheists and Oaths

We cannot pretend that an oath is something other than someone calling upon God as witness and judge.

Of Atheists and Oaths
Photo by Liv Cashman / Unsplash

Should atheists offer testimony before a church court? Given the desirability of truthful testimony, the relevance of the ninth commandment to this question is obvious: Can someone be trusted not to bear false witness against his neighbor, if he refuses to call upon God as witness and judge? That’s an important question, and one we should consider.

But it’s not the most important question. The third commandment is determinative in a way the ninth commandment is not. The Westminster Assembly understood the connection between honoring God’s name and telling the truth in court. Indeed, the word perjury occurs only once in the Westminster Larger Catechism, and the catechism identifies perjury as a sin forbidden by the third commandment, not as a sin forbidden by the ninth.

The most pressing question is not whether an atheist will bear false witness. The most important question is whether we can neglect to require God’s name when we must require it. The third commandment clearly teaches us that we must not walk away from God’s name when it is required. Because an oath is one such instance, atheists should not offer testimony before church courts, so long as church courts require oaths.


Before we consider the importance of the third commandment, let me say something about a question raised by the ninth: Can an atheist speak truthfully about judicial matters, even if doing so will harm his own interests? Here I may differ from those with whom I am in overall agreement. My answer is straightforward: of course. I happily grant that many atheists will tell the truth with great care.

But the question isn’t whether atheists can tell the truth (of course they can) or whether they will tell the truth (presumably many will). The question instead is whether their promise to tell the truth impresses upon them an obligation to tell the truth that is equivalent to a believer’s oath that calls God as witness and judge. The answer to that different, but related, question? Of course not. An oath is greater than a promise, just as a promise is greater than a mere statement. An atheist can recognize the difference between an oath and a promise, even if he believes it is irrational. God does not exist, he may say, but if God did exist, then calling upon him as witness and judge would be a very solemn thing, indeed.

So let’s be clear: The following arguments do not depend upon a characterization of atheists as uniquely horrible or especially prone to lie. On the contrary, the arguments assume that many atheists will tell the truth. The issue is not the moral character of the atheists. The issue is the nature of the oaths themselves, and the third commandment.


Let’s make our case explicit:

  1. Oaths just are statements that call God as witness and judge.
  2. Atheists cannot make statements that call God as witness and judge.
  3. To say atheists can take an oath without calling God as witness and judge is a contradiction, because that’s just what an oath is.
  4. To permit an oath without using God’s name is a violation of the third commandment, because God’s name is required for an oath.

We will assume that everyone agrees with statement 2, that atheists cannot call God as witness and judge. So the first argument focuses on statement 1, on what an oath is. The claim is that a so-called “oath” without God is actually not an oath at all. The conclusion of the first argument, statement 3, follows from the first two statements: To say that an atheist can take an oath is to say that someone who claims not to believe in God can claim to believe in God as witness and judge, which is incoherent.

The second argument focuses on the honor due God’s name. For me, this argument, which concludes with statement 4, is determinative. The first argument shows that calling God as witness and judge is required for an oath. The second argument shows how the third commandment forbids us from neglecting to use God’s name when his name is required. Because oaths require God, we cannot neglect to mention him in them.


First, let’s ask what oaths are. To address this question, let’s think about how we identify anything at all. Usually, we appeal to a thing’s specific difference, that is, what distinguishes what we are talking about from other things that resemble it. For example, if you ask for a spoon, and I give you a knife, you’ll say you want the scooping thing, not the cutting thing. By contrast, if you ask for a spoon, and I bring you a shovel, you’ll say you want a utensil, not a digging tool. We identify things by acknowledging what they resemble and by emphasizing what distinguishes them from everything else.

Back to oaths: What is the specific difference between solemn speech and an oath, between stating something firmly and swearing to it? One word: God. In an oath, someone calls God as witness and judge. Indeed, an oath just is calling God as witness and judge. Put another way, there is no such thing as an oath without God as witness and judge. There is only one kind of oath, the one that calls upon God as witness and judge. Solemn speech that does not appeal to God may be called an oath by others, but calling something an oath does not make it an oath. Calling upon God as witness and judge makes something an oath.

How can I be so clear about oaths? Three things: Scripture, the Westminster Standards, and the practice of oaths in the history of the world.

My case rests considerably more on Scripture and the Standards, but I’ll first say something briefly about history. A survey of pagan oaths offers this concluding remark: “Even if effective military means were at hand, the gods provided the only written sanction. A treaty was not actually in effect unless it involved the solemn affirmation by the divine that one would be faithful to the details of the agreement” (Donald L. Magnetti, “The Function of the Oath in the Ancient Near Eastern International Treaty,” The American Journal of International Law 72:4 (1978), 829). The oaths of the Vulture Stele call upon different gods as witness and judge; one early Mesopotamian king wrote to another saying, “Let us swear a great oath by the gods.” Hundreds of years later, the Hittites made a variety of treaties, which included gods as witnesses as well as curses and blessings. Likewise, the ancient Hippocratic Oath calls upon Apollo and other gods. Rather than taking each century in its turn, let’s move forward to this more recent oath:

I do believe in one God, the creator and governor of the universe, the rewarder of the good and the punisher of the wicked. And I do acknowledge the Scriptures of the Old and New Testament to be given by Divine inspiration.

This oath for legislators came from the 1776 constitution of “tolerant Quaker Pennsylvania,” in the words of Mark David Hall. Even the current Pennsylvania constitution offers unique protection against disqualification from office for those who acknowledge “the being of a God and a future state of rewards and punishments.” God is witness, and God is judge. Other states have more stringent provisions about unbelievers, but these provisions have been unenforceable since Torcaso v. Watkins, 367 U.S. 488 (1961). Nevertheless, they offer textual evidence for my claim that the difference between a solemn declaration and an oath just is calling God as witness and judge.

But who cares? We have developed a better political system than the Hittites, and we have progressed beyond Euclidian geometry in mathematics. Why should we cling to a pre-1961 consensus — a consensus the civil authority has itself abandoned — if doing so prevents key witnesses from giving crucial testimony?

First, we are speaking here of church courts. In civil matters, someone who does not believe in God has an externally enforced motivation to tell the truth. The threat of a perjury conviction serves as an incentive to fulfill the requirements of one’s pledge. Even if you do not think God will judge you, the state may, and the amount of information collected on each one of us increases the likelihood that attempts at deceit will be discovered. We can treat civil oaths without God not as actual oaths but as recognitions by testifiers that they will perjure themselves if they testify falsely. Of course, such is not the case for a church court. There is no threat of perjury, and, for the atheist, no threat of excommunication, either. He is not in the church, so he can hardly be expelled from it. By contrast, in the civil realm, the threat of perjury sharpens the mind.

But, most importantly, the Scriptures and the Standards themselves understand oaths as solemn declarations calling God as witness and judge. To define oaths differently is to depart from their clear teaching. We cannot change what something is merely by speaking of it differently. Saying that a woman is a man or a man is a woman does not make it so. Calling a godless promise to tell the truth an oath does not make it an oath.

Consider the description of an oath in Solomon’s prayer in 2 Chronicles 6:22–23:

“If a man sins against his neighbor and is made to take an oath and comes and swears his oath before your altar in this house, then hear from heaven and act and judge your servants, repaying the guilty by bringing his conduct on his own head, and vindicating the righteous by rewarding him according to his righteousness.”

God serves as both a witness (“then hear from heaven”) and a judge (“and act and judge your servants”). Scripture is clear on what an oath is and what an oath is not. The same can be said for the Westminster Confession of Faith, which declares that “a lawful oath is a part of religious worship, wherein, upon just occasion, the person swearing solemnly calleth God to witness what he asserteth, or promiseth, and to judge him according to the truth or falsehood of what he sweareth” (WCF 22.1).

Correct. In an oath, God serves as witness and as judge. That’s a definition of an oath in the affirmative. In the next paragraph, we get the negative: “The name of God only is that by which men ought to swear” and “to swear at all by any other thing, is sinful, and to be abhorred” (WCF 22.2). So we swear an oath in God’s name, and we do not swear an oath by anything else.

Now to conclude this first argument: To speak of an atheist swearing an oath without calling God as witness and judge is to speak incoherently. Consider a parallel: a bachelor just is an unmarried man. That’s what a bachelor is. If someone speaks of his married bachelor friend, he shows he does not know what the word bachelor means. So, too, an oath calls God as witness and judge.  That’s just what an oath is. If someone claims to take a godless oath, he shows he does not know what an oath is. If a man is married, he’s not a bachelor. If a solemn promise does not include God as witness and judge, it’s not an oath.


The first argument considers what an oath is; atheists cannot take oaths, because we cannot pretend that an oath is something other than someone calling upon God as witness and judge. The second argument, to which we now turn, focuses on the honor due God’s name. Put simply, we must use God’s name in an oath, and we cannot circumvent this responsibility.

Westminster Larger Catechism 112 asks, “What is required in the third commandment?” According to the Westminster Standards, the third commandment requires, among other things, that oaths be “be holily and reverently used in thought, meditation, word, and writing; by an holy profession, and answerable conversation, to the glory of God, and the good of ourselves, and others.” An attempt to make an oath that makes no mention of God robs God of the glory due him as the witness and judge of all we say.

Westminster Larger Catechism 113, on the sins forbidden in the third commandment, makes explicit the sinfulness of avoiding God’s name in oaths. Now we may think of the third commandment most often in the context of cursing or blaspheming, and the answer to question 113 does not disappoint us. But a proper reverence for God’s name requires more than merely avoiding the misuse of that name. The third commandment also forbids the neglecting of God’s name when it is required.

Indeed, the answer to Westminster Larger Catechism 113 begins with the sin of not using God’s name when it is required: “The sins forbidden in the third commandment are, the not using of God’s name as is required.” We must not commit the sins of “violating of our oaths and vows, if lawful; and fulfilling them, if of things unlawful.” That is, if we swear a lawful oath and violate it, we have sinned against God’s name and broken the third commandment. If we have sworn an unlawful oath, then we cannot dishonor God’s name by pretending that we must do some wicked thing in order to glorify him. Westminster Larger Catechism 113 concludes with the sins of “being ashamed of it [God’s name], or a shame to it, by unconformable, unwise, unfruitful, and offensive walking, or backsliding from it.”

We cannot backslide from the name of God. We cannot uncomfortably, unwisely, unfruitfully, and offensively walk away from God’s name. Nor can we encourage others to do so by permitting such a violation of the third commandment in the courts of the church. We cannot call on an atheist to embrace the gospel in the name of God and tell him at the same time that he can reject the name of God required for an oath. We should not hope he will fulfill the ninth commandment if we permit him to violate the third.


The question about atheists and oaths does not need to be resolved by making philosophical arguments about the rational instability of atheism; by exploring sociological data suggesting atheists are an honest bunch; or by offering probabilistic judgments about whether a certain atheist will tell the truth in a particular instance. These questions, though interesting and helpful, do not determine the answer to the question of whether atheists can take oaths in a church court.

Instead, we must look to an oath itself. An oath requires God as witness and judge. To suggest that an atheist can offer an oath contravenes the meaning of an oath.

We must look to the third commandment. Since an oath requires an appeal to God as witness and judge, we must give God the glory that is due him in each and every oath. A church court must not be ashamed of God’s name, or a shame to it.