Biography - conversion
Checkmate at last
Lewis's conversion to Christianity was not a sudden experience. He always claimed it was logical and rational, not emotional. His influences were, as always, books and a few close friends.
Inspired by his reading, Lewis's personal philosophy had been slowly approaching theism (belief in a god) under another name: he came to believe in a universal spirit without yet calling it God. He knew that his position was confused. In Surprised by Joy he likens the following process to being hunted down by God, or even being defeated by him in a game of chess.
Lewis had several Christian friends at Oxford, including Hugo Dyson and the Catholic J.R.R. Tolkien, with whom he often argued philosophy and religion. A chance remark by another acquaintance, T.D. Weldon, caused Lewis to rethink what he still was calling "the Christian myth": Weldon, known for his cynicism, thought that the evidence for Jesus's life and resurrection was remarkably good. Lewis read the Gospels and was struck by the thought that they did not sound like fiction: the writers seemed too unimaginative to have made the whole thing up; the Gospels read more like reports than stories.
Albert Lewis died in 1929. His death caused Jack to feel guilty about deceiving him. Jack also believed he could feel Albert's presence after his death. At this time Warren and Jack were both thinking of becoming Christian, although the idea of churchgoing was still unappealing to Jack and he did not accept many aspects of the Christian theology.
On September 19, 1931, Lewis, Dyson and Tolkien took a night-time stroll and began a conversation about myth. They walked and talked until morning. Tolkien convinced Jack that myths were God's way of preparing the ground for the Christian story. The stories of resurrection throughout history were precursors to Jesus's true resurrection: Christianity was the completion of all the mythology before it. Dyson's contribution was to impress upon Jack how Christianity worked for the believer, liberating them from their sins and helping them become better people. His remaining arguments were being demolished. Jack Lewis was about to be checkmated.
The final stage in Jack's conversion to Christianity took place three days later and was typically unconventional. He and Warren were travelling by motorcycle to Whipsnade zoo: "When we set out I did not believe that Jesus Christ is the Son of God, and when we reached the zoo I did." Jack wrote a book called The Pilgrim's Regress that told the story of his conversion in allegorical form.
Lewis also realised that his old experiences of 'Joy' had been pointers, reminding him that he was made for another world: he now reinterpreted them as longings for heaven, for God. He felt 'Joy' again many times in his life, but no longer attached the same importance to the experiences.
It was after his conversion that Lewis began writing his Christian apologetic books.