C.S. Lewis became a Christian in 1931 after a prolonged intellectual and spiritual change.
Lewis had returned to belief in God by 1930, but he later described his conversion to Christianity as taking place in 1931. In Surprised by Joy, he famously characterized himself as “the most reluctant convert in England.” His conversion followed years of reading, reflection, and discussions with Christian friends.
J.R.R. Tolkien and Hugo Dyson were especially important in Lewis’s movement toward Christian belief. A conversation with them at Oxford in September 1931 helped Lewis think about Christianity, myth, and the possibility that Christian claims were historically grounded rather than merely symbolic.
The exact wording of Lewis’s personal accounts can cause confusion because he described several stages: belief in God, acceptance of Christianity, and later changes in denomination. The stable date commonly given for his conversion to Christianity is 1931.