Why you can't believe anything - Without God

In an age dominated by scientific materialism, many assume that human reason is a reliable tool for discovering truth. We trust our brains to navigate complex problems, formulate arguments, and arrive at conclusions about reality itself—including the conclusion that there is no God. But this trust in reason rests on a profound contradiction if the universe is purely the product of unguided, random processes.

Consider the origin of the human brain. According to naturalistic evolution, our cognitive faculties emerged through billions of years of random mutations filtered by natural selection. Selection favors traits that enhance survival and reproduction, not necessarily those that produce true beliefs. A brain wired for adaptive behavior—avoiding predators, finding food, or attracting mates—might thrive even if filled with false or unreliable convictions.

As philosopher Alvin Plantinga articulates in his Evolutionary Argument Against Naturalism (EAAN), the probability that our cognitive faculties are reliable for truth-seeking, given naturalism and evolution, is low or inscrutable. If our beliefs are shaped primarily for survival rather than truth, why trust them when they tell us that naturalism is true? This creates a self-defeating loop: the very reasoning leading to naturalism undermines confidence in that reasoning.

C.S. Lewis explored a similar idea in his Argument from Reason. He argued that rational thought cannot arise from irrational, non-purposeful causes. If all mental processes are merely the byproduct of blind physical events—atoms colliding in the brain according to physical laws—then there is no ground for believing those processes yield valid inferences. Lewis wrote: "If minds are wholly dependent on brains, and brains on biochemistry, and biochemistry (in the long run) on the meaningless flux of the atoms, I cannot understand how the thought of those minds should have any more significance than the sound of the wind in the trees."

In a purely material universe, reason becomes an unintended side effect of random processes, continually influenced by chance events like cosmic rays or genetic mutations. How, then, can we rely on conclusions drawn from such a system? To claim "there is no God" using reason is to saw off the branch on which one sits.

This dilemma points to a necessary foundation for trustworthy reason: a purposeful, rational source that designed our minds to align with truth. The biblical worldview provides this foundation. God, as an eternal and perfectly rational being, created humans in His image (Genesis 1:27), endowing us with faculties capable of knowing truth because they reflect His own rational nature. As Lewis put it, "Reason—the reason of God—is older than Nature, and from it the orderliness of Nature... is derived."

Presuppositional thinkers like Cornelius Van Til and Greg Bahnsen developed this into the Transcendental Argument for God (TAG): the existence of intelligible experience, laws of logic, and reliable reasoning presupposes a rational God. Without Him, these become inexplicable; non-Christian worldviews reduce to absurdity when pressed for an account of rationality itself.

Naturalists borrow from the Christian worldview—assuming logic, uniformity of nature, and the reliability of reason—while denying its foundation. But consistency demands acknowledgment: if we can trust our reason to conclude anything meaningful about reality, it is because God has granted us that ability.

Ultimately, atheism undermines the very tools it uses to defend itself. True knowledge and reliable belief require a God who grounds reason in purpose rather than chance. Without Him, skepticism swallows all claims, including skepticism itself. To believe anything with confidence—including the truths of science, morality, or philosophy—one must ultimately presuppose the God who makes belief possible.