The fundamental tools of human cognition, logic, reason, and critical thinking, require a robust metaphysical foundation that secular worldviews cannot provide.
Metaphysical Naturalism, the view that the physical cosmos is all that exists, fails because if human thoughts are merely the result of blind neurochemical reactions, there is no justification for trusting them as rational insights into truth. Unguided evolution selects for survival, not truth. If our cognitive faculties are evolved merely for adaptive behavior, the probability that they produce true beliefs is low. Thus, the naturalist has a defeater for trusting their mind, including their belief in naturalism itself.
Conventionalism, the idea that logic is a human linguistic invention, should be rejected because logic is universal and invariant; a society cannot validly decide that contradictions are true.
The theory of Brute Facts, that logic simply "is" without explanation, can be dismissed for violating the Principle of Sufficient Reason, which undergirds all scientific inquiry.
Platonism, which views logic as abstract objects existing in a non-physical realm, is also wanting. It fails the access problem: if logic is causally inert and outside space-time, physical humans could never know it. Furthermore, propositions possess intentionality (they are about things), which is a property unique to minds, not abstract objects.
In contrast, there is Divine Conceptualism (or Theistic Conceptual Realism). It posits that laws of logic are necessary truths. Since truths are propositions and propositions are mental thoughts, necessary truths must be the thoughts of a necessary, eternal Mind, i.e. God. This avoids the Euthyphro Dilemma by grounding logic not in God’s arbitrary will, but in His essential, immutable nature.
Thus, God is the necessary precondition for any rational experience. To argue against God, a skeptic must rely on the uniformity of nature and laws of logic, which only make sense in a theistic universe. Thus, atheism is self-refuting because it borrows capital from the worldview it seeks to deny.
Humans can reason because they are designed to reflect the Supreme Mind. This also explains the normativity of logic; we feel we ought to be logical because irrationality is a moral rebellion against the nature of reality and God. Without God, reason collapses, making theism a strict philosophical necessity for critical thinking.