 Tolkien's devout Roman Catholic faith was a significant factor in the conversion of C. S. Lewis from atheism to Christianity, although Tolkien was dismayed that Lewis chose to join the Church of England.He once wrote in a letter to Rayner Unwin's daughter Camilla, who wished to know what the purpose of life was, that "[i]t may be said that the chief purpose of life, for any one of us, is to increase according to our capacity our knowledge of God by all the means we have, and to be moved by it to praise and thanks.