C.S. Lewis publicly embraced Christianity in 1931 after returning to religious belief.
Lewis had been raised in the Church of Ireland but became an atheist during his adolescence. Over time, conversations with writers and scholars, especially J.R.R. Tolkien and Hugo Dyson, contributed to his renewed interest in Christianity. Lewis described his conversion as a gradual movement from atheism to theism and then to Christian belief.
He wrote that he became a believer in 1931, and later explained parts of this journey in autobiographical works such as Surprised by Joy. His conversion transformed the direction of his writing. He began producing apologetic works, sermons, devotional books, and fiction shaped by Christian ideas.
Lewis was an Anglican, not a Roman Catholic, and his public work generally addressed broad Christian audiences. Mere Christianity, The Problem of Pain, and the BBC broadcasts later collected under that title made him one of the most influential Christian communicators of the twentieth century.