Which C.S. Lewis autobiography describes his conversion to Christianity?

C.S. Lewis’s autobiography describing his conversion to Christianity is Surprised by Joy. The book was published in 1955 and traces his intellectual and spiritual development from childhood through his return to Christian belief.

Lewis discusses his early imaginative life, his education, his experience in the First World War, and his changing views about religion. He describes “joy” as a powerful longing or desire that appeared unexpectedly through literature, nature, and imaginative experience. That idea became central to how he explained his spiritual journey.

Lewis had been an atheist for a period before returning to theism and then Christianity. His friendships with Christian writers, including J.R.R. Tolkien and Hugo Dyson, contributed to the discussions that influenced him during the early 1930s.

Surprised by Joy is sometimes mistaken for A Grief Observed, which concerns Lewis’s mourning after the death of his wife, Joy Davidman. The two books deal with different periods and purposes in his life.