The Beloved Classic on What All Christians Believe One of the most popular introductions to Christian faith ever written, Mere Christianity brings together Lewis’ legendary broadcast talks during World War Two. Here, Lewis provides an unequaled opportunity for believers and nonbelievers alike to hear a powerful, rational case for the Christian faith. A collection of scintillating brilliance, Mere Christianity remains strikingly fresh for the modern reader and at the same time confirms CS Lewis’s reputation as one of the leading writers and thinkers of our age.