In 1988, the atheist philosopher A. J. Ayer had such an adventure when he choked on a piece of smoked salmon and his heart stopped for a few minutes. Soon afterward, Ayer reported that his near-death experience, in which he saw a red light that seemed to govern the universe, “slightly weakened my conviction that my genuine death... will be the end of me.” But he later dismissed it as a hallucination caused by a temporary lack of oxygen in his brain.
--Jim Holt, NYT Magazine, on the unbending faith of unbelievers
...to my thinking, miracles are never a stumbling-block to the realist. It is not miracles that dispose realists to belief. The genuine realist, if he is an unbeliever, will always find strength and ability to disbelieve in the miraculous, and if he is confronted with a miracle as an irrefutable fact he would rather disbelieve his own senses than admit the fact. Even if he admits it, he admits it as a fact of nature till then unrecognised by him. Faith does not, in the realist, spring from the miracle but the miracle from faith. If the realist once believes, then he is bound by his very realism to admit the miraculous also.
--Fyodor Dostoevsky, The Brothers Karamazov, on A. J. Ayer's dismissal