A person who says “God does not exist” contradicts himself in at least three ways:
1) By presupposing the existence of objective values.
As soon as the atheist chooses to say, “God does not exist”, he makes a choice. He chooses to make this particular claim instead of saying or doing any of the unlimited number of other things he could say or do. Somehow he places more value in articulating this claim than in saying or doing any other thing. But on atheism no thing is really more valuable than any other thing. Everything has zero value, and therefore it makes no sense to say or do one thing, instead of saying or doing any other thing. For value judgements to make sense we need to have an absolute standard, or absolute reference point, to measure our values against. In the absence of such an absolute standard, or absolute reference point, values are simply relative and subjective, rendering it impossible to claim that one thing is more or less valuable than any other thing. Or that anything has any value at all.
Values are a function of consciousness. They exist in minds. We do not see values flying around in the air, hanging on trees or lying on the streets. They cannot be studied under a microscope. It should be obvious that fallible and limited human minds cannot establish absolute values. What to speak of establishing an absolute standard, or absolute reference point, against which to measure values.
Even if we, for the sake of argument, accepted that we humans could establish absolute values, this would result in contradictions. One human being could make it an absolute truth that human life is absolutely valuable, while another human being could make it an absolute truth that the absence of human life is absolutely valuable. This would make human life both absolutely valuable and not absolutely valuable at the same time, which is a contradiction.
The obvious cause of absolute values is an absolute mind, God, with absolute power to make sure that no other person or entity can, will change, or overrule His created values. So by claiming, “God does not exist”, the atheist borrows absolute values from the theistic worldview, and thus he actually confirms the existence of God, making his claim self-contradictory.
2) By presupposing the existence of truth, knowledge and certainty.
The claim, “God does not exist”, is a claim to certain knowledge. It is a truth claim. But on atheism, how can we account for truth, knowledge and certainty? If we ask the atheist how he knows A, he will say that B is the cause of A. If we ask him how he knows B, he will say that C is the cause of B. In this way he is pushed into an infinite regress of proofs where he is unable to find an absolute starting point that will justify his claims to truth, knowledge and certainty. The atheist might try to argue that his reason and sense perception is the basis of his knowledge. But our reason and sense perception are fallible, and thus ultimately not trustworthy. Thus the atheist could actually be wrong about everything he claims to know. The only way he can attempt to justify his reason and sense perception is by using his reason and sense perception. He is thus caught in a vicious circle, a logical fallacy. In order to escape this vicious circle he has to either 1) be all-knowing, or 2) have knowledge from someone who is all-knowing. Why? Because even if he thought he had access to some knowledge, this alleged knowledge could be contradicted by knowledge from areas he has no access to.
All this means that we cannot make any claim to truth, knowledge and certainty without appealing to an all-knowing being, God. So by claiming, “God does not exist”, the atheist actually, again, presupposes the existence of God. He is borrowing truth, knowledge and certainty from the theistic worldview, and thereby contradicting himself, again.
3) By presupposing the existence of the laws of logic.
Language presupposes the laws of logic. Without logic governing our language we are not able to communicate. Everything we say would be unintelligible noise. Nonsense. Our intelligence, in its sane condition, reasons according to the laws of logic. Acceptance of the laws of logic are programmed into the intelligence from our birth. But the laws of logic could not exist without God. The laws of logic are non-physical or abstract, objective, absolute, changeless, universal and eternal. They are made of thought-stuff, not of perceivable matter. They cannot be accounted for in an atheistic universe. How can laws that are non-physical or abstract, objective, absolute, changeless, universal and eternal arise from matter, since matter have more or less the opposite characteristics? The laws of logic, like values, truth, knowledge and certainty, require a personal God (one with the ability to think) for their existence and continued maintenance.
Another point about logic is that we use two-valued logic, which means we divide propositions into “true” or “false”. There is no third option. But what if nature, or some higher, but limited, and perhaps evil being, has programmed us to think in terms of two-valued logic, while reality functions according to, and can only be understood by, a type of many-valued logic? To defend the use of two-valued logic we would have to use two-valued logic. And thus we are caught in a vicious circle. We would need an absolute being, with absolute power and knowledge, to reveal to us which kind of logical system to use. Theists have this option, because they depend on a revelational epistemology. Atheists do not have this option, and thus they have to borrow their faith in two-valued logic from the theistic worldview. Thus they are contradicting themselves by implicitly confirming God’s existence through their use of the laws of logic.
There is a fourth way in which the atheist usually contradicts his own denial of God.
4) By presupposing the existence of objective morality and ethics.
It is safe to say that whenever the atheist debates the existence of God, he expects the debate to be conducted in a morally appropriate way. He thinks the debaters ought to follow the rules of logic, be honest and exhibit at least a certain degree of civilized behaviour. But these are moral values, and moral values cannot be accounted for in an atheistic universe. On atheism there is no absolute standard against which to measure our actions. Morality is reduced to relativity and subjectivity. This means that all actions actually have zero moral value. Thus it makes no sense to prefer one moral value over another, or to even accept any moral values at all.
By presupposing moral values the atheist is, again, actually presupposing the existence of God, and borrowing from the theistic worldview.
We have seen how the atheist contradicts his affirmation of the non-existence of God in at least 3 or 4 different ways. The same is the case with agnostics, or people who claim they do not deny the existence of God, but simply have the absence of belief in Him due to having seen no evidence in favour of His existence. They all appeal to values, truth, knowledge and certainty, laws of logic and moral values, all of which cannot be accounted for in the absence of God. The positive atheist, the negative atheist, and the agnostic as well, are really using God to deny God. To hold any of these positions is therefore self-contradictory.
The conclusion is that atheists are first and foremost theists, since, as we have seen, we first have to accept God before we can deny Him. In logic, a proposition must be true, if its negation is self-contradictory. This means that the statement, “God exists”, must be true, since it is self-contradictory to deny it. But the atheist, because he loves his selfish desires more than God, goes ahead and denies God anyway, and thus reduces his position to self-contradictory absurdity.