C.S. Lewis publicly announced his return to Christianity in 1931. His conversion followed years of intellectual and personal change after a period in which he described himself as an atheist.
Lewis had been raised in the Church of Ireland but became increasingly skeptical during adolescence and early adulthood. His return to belief was influenced by conversations with colleagues and friends, including J.R.R. Tolkien and Hugo Dyson. Lewis later described moving first toward theism and then toward Christianity.
A frequently cited milestone is a conversation with Tolkien and Dyson at Oxford in September 1931. Lewis later wrote that he became a Christian in 1931, although the stages of his conversion developed over time rather than in one instantaneous event. He discussed this journey in Surprised by Joy, published in 1955.
The year should not be confused with the publication dates of his best-known apologetic books. Mere Christianity appeared in book form in 1952, after wartime radio talks, while The Problem of Pain was published in 1940.