C. S. Lewis was probably the most articulate defender of the Christian faith in the latter half of the twentieth century. But he was an atheist when he set off on a weekend holiday during his university years. He purchased a novel from the kiosk in the railroad station for reading during his trip. It was a novel by George MacDonald, chosen haphazardly. But as Lewis read, he later reported, his imagination was converted; the rest of him would follow later. How strange that the Wind [-- the Sprit --] would blow through a novel one might buy at a railroad newsstand!
But that wasn't all. Though Lewis had now acknowledged the existence of God, he did not believe in the primary essential of the Christian faith, that Jesus Christ is the Son of God. Then one sunny morning, while being driven to Whipsnade on a motorcycle by a friend, Lewis set out not believing in Jesus Christ, but "when we reached the zoo I did." It wasn't the product of thought, though Lewis was a scholar; nor was it, he says, a matter of great emotion. "It was more like when a man after long sleep, still lying motionless in bed, becomes aware that he is now awake" (Surprised by Joy, 237).
-- J. Ellsworth Kalas in New Testament Stories from the Back Side