The Very Concept of Truth Is Impossible Without God

By Joel Settecase / Original posting: May 10, 2019. Updated February 13, 2023.

Much ink has been spilled by apologists over the centuries, demonstrating that the Christian worldview is true. But what if the very concept of truth were impossible without first believing in the Christian worldview, in the truth of Scripture and the God revealed therein?

This article was originally published as a four-part series on Joel Settecase’s blog.

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I have been seeking out conversations with atheists on Twitter lately (though they usually find me), and a recent one got me thinking. In speaking with this chap, I made the point that truth presupposes God, and that faith in God is the necessary precondition to any truth-seeking endeavor.

He asked me why, and in the course of elaborating, I asked him if he believed in absolute truth. To that, he replied No, he did not.

This raised two questions that I realized I needed to do some more thinking about:

First, why does truth presuppose God? (I’ve written before on why scienceand logic presuppose God, but why truth?) I believed this was the case, but could I articulate it?

Second, is it an appropriate dodge on the part of the atheist to simply declare he doesn’t believe in truth, or absolute truth, and therefore avoid belief in God? Again, I knew this couldn’t be the case, but could I express why that was?

Jesus says that truth is essential for freedom (John 8:32), and here this guy was denying the truth–and therefore the possibility of his own freedom. As a follower of Jesus, I wanted him to be free. To help me communicate that (to him and others), I wanted to be able to explain what truth is, and how truth connects to God.

So I undertook the task of defining what exactly truth is, and why belief in God is the necessary precondition for truth–and why simply saying that truth doesn’t exist isn’t an effective move.

The Difficulty of Definition

We must begin with a definition of the word truth, without just defining it by itself. This is harder than it would seem. Truth is one of those words that we use all the time, but we don’t really think about what it meansbecause it seems so self-evident: “Truth is… what’s true.”

Webster’s says truth is “the state of being the case.” But then, this feels incomplete. What is in the state of being the case? What case? What sort of thing can be true? Can a rock be “true?” No, truth is a quality of propositions, it cannot be possessed by things. A rock cannot be true, but the statement, “the rock is on the table” can.

For the purposes of this article, then, we will build a more complete and useful definition of the word truth–a true definition–and then demonstrate that truth is an impossible without God.

Truth and Language

So we have seen that truth is an attribute of propositions, and propositions are by definition linguistic; they are statements made in a particular language, whether English, French, Koine Greek or something else. Propositions, being a function of language, only make sense if they accord with the laws of language (grammar and syntax, etc., but also they must contain real words that are meaningful within that language).

It makes sense to say in English, “The rock is on the table,” but not “The rock fleurglob table the.” That’s nonsense, not English. Language isn’t freeform, it has rules. That collection of “words” doesn’t follow the rules of the language and therefore it’s incomprehensible, meaningless. Such a “proposition” really isn’t a proposition, and it makes no sense to ask whether it is “true.”

So the first criterion of truth is that a proposition accords with the rules of language. It is comprehensible.

Truth and Logic

Next, for any proposition to be sensible or possible, it must accord with the laws of logic. I have written about logic before, but in short, a logical proposition must not contradict itself (the Law of Noncontradiction). It must refer to what it refers to (the Law of Identity). It must affirm a state of affairs or its opposite, but not both (the Law of Excluded Middle).

These logical laws govern all thought and language. They are transcendentals, in that they transcend any one particular language or culture. Whereas vocabulary, grammar and syntax change from language to language, the laws of logic are unchanging. They are also immaterial, universal, and knowable.

A proposition (in any language) that contradicted itself or otherwise violated logic could not be meaningful, let alone true.

The second criterion for truth, then, is that a proposition accords with the laws of logic. It is coherent.

Truth and Reality

Finally we come to the third criterion, and this is the one most people think of when they think of truth. A true proposition is one that describes the actual state of affairs. It affirms the real world the way the real world actually is.

In this, it is necessary to believe that there actually is such a thing as “the real world.” More on this in a minute.

Therefore the third criterion for truth is that it accords with reality. It is correspondent.

All Three Criteria Presuppose God

We may now define truth as the quality of a proposition that is comprehensible in terms of language, coherent with regard to logic and correspondent to actual reality.

Now we can move on to why truth presupposes God. This is the case because all three criteria individually require God in order to be meaningful or real.

Comprehensibility Presupposes God

How does language presuppose God? Language presupposes God because it assumes that minds are designed to communicate and understand ideas. Further, the use of language assumes the uniformity of nature, that the future will be like the past.

That is, the speaker (and the hearer) must believe that words will mean the same thing in five seconds that they meant five seconds ago. “Is” will always mean “is” and never “is not.” This requires a stability to the universe that can only be explained by the faithful, unchanging, good God of Scripture.

Coherence Presupposes God

What about logic? Logic presupposes God because it assumes that there are true, immaterial, unchanging, good, universal and knowable laws that govern thought and speech. God is all of these things. If you believe in God and the truth of the Bible, it makes sense that the universe would be governed by such laws. It also makes sense that human beings, created in the image of God, would think and speak logically.

Could an atheist still affirm belief in logic? Of course! Atheists do this all the time. The question is, can they do so consistently? No.

Unbelief in God makes belief in logic simply a matter of random, subjective opinion (not possible).

Worse yet, an atheist evolutionist, who believes that his mind (which is just his brain) is the product of time + chance + millions of years and merely “aimed” at survival and reproduction (unrelated to actual truth-seeking), must believe that his own belief in logic is determined solely by his genes. Belief in logic isn’t rational; by believing in logic he’s merely dancing to his DNA. A mind evolved by chance could never “step outside itself” to analyze its own conclusions, including its conclusions about logic. On such a worldview there is no reason to believe in logic.

Correspondence Presupposes God

Belief in reality presupposes God because it assumes there is a state of affairs external to one’s own mind. There is a world which is objectively “out there.” That world is intelligible; it is capable of being known.

Similarly, this also presupposes that one’s mind is able to know something about the external world. In order to be able to make correspondent propositions about the world, the human mind  must also correspond to the world in such a way that knowledge about the world is possible, and conclusions about the world may be correct. 

The Bible teaches that God created man in his image, with the ability to study the world and gain true knowledge from it (see these verses related to the intelligibility of nature). Without God there’s no reason to believe this.

So far we’ve defined truth according to three criteria, defined those criteria and seen how each of them presuppose God. Now let’s examine why truth is a problem for those who deny God’s existence.

The Atheist’s Problem With Truth

However you look at it, truth presupposes God.

Atheists then have a huge problem. This brings us back to my Twitter discussion partner–the one who denied the existence of absolute truth.

To affirm the existence of truth is to presuppose the existence of God and the truth of what the Bible teaches about God, the world and humanity. 

On the other hand, to deny truth is to deny the possibility of saying anything is “true.” This also precludes anyone from saying that it is true that God does not exist. If there is no truth, than the fundamental proposition of atheism, “God does not exist,” cannot be true.

And what about the dodge that my discussion partner made, by denying absolute truth? He didn’t take it this far, but I will make the argument for him. What if truth exists, just not absolute truth? Is that possible?

Absolute truth is just truth that is true universally and unchangingly. Without getting too deep into the weeds, every true proposition is universally true, given enough details.

As an example: “Joel Settecase is a 13-year-old boy” was true, but it is no longer true. However, it is absolutely true that on October 21st, 1996, I was a 13-year-old boy. That statement is absolutely true. It is also absolutely true that I just typed that. And it is absolutely true that you are reading these words at the current moment in time.

So then, truth exists, and absolute truth exists absolutely. There is no way around this.

Back to that Twitter Conversation

I had affirmed to my discussion partner that faith in God is necessary in order to pursue absolute truth. He asked me why, yet he asked this while denying the very existence of absolute truth.

He perhaps couldn’t see how his own worldview made his question incoherent.

On his worldview, it was true that truth didn’t exist. Truth both existed and didn’t exist–a logical contradiction. And he wanted to know how belief in God was necessary to pursue truth according to that definition. But this is a logical impossibility. I was not interested in defending the pursuit of a logical impossibility. I therefore wanted to establish that truth only made sense from the biblical worldview in the first place.

When I pushed him on whether it was absolutely true that truth does not exist, he told me that I apparently wasn’t interested in having a conversation, and he ended it.

Truth Presupposes God

None of the above proves that atheists and unbelievers can’t know anything true. They know all sorts of true things. Truth is inescapable. Rather, all this shows that atheism cannot account for the existence of truth.

The Bible, on the other hand, is full of truth, and it centers on the One who is the embodiment of truth himself: the Lord Jesus (John 14:6). To know him is to  is to know truth. That knowledge is bound up with obeying him as Lord. And then, Jesus says, “the truth will set you free.”

This is apologetics; I hope it made you think.