Is Atheism thoughtful?
Supposing there was no intelligence behind the universe, no creative mind. In that case nobody designed my brain for the purpose of thinking. It is merely that when the atoms in my skull happen, for physical or chemical reasons, to arrange themselves in a certain way, this gives me as a by-product, the sensation I call thought. But if so, how can I trust my own thinking to be true? Its like spilling a milk jug and hoping that the way it splashes itself will give you a map of London. But if I can't trust my own thinking, of course I can't trust the arguments leading to atheism, and therefore I have no reason to be an atheist or anything else. Unless I believe in God I cannot believe in thought. So I can never use thought to disbelieve in God.
CSLewis The Case for Christianity