One of the most popular introductions to Christian faith ever written, Mere Christianity has sold millions of copies worldwide. In this book C. S. Lewis, a 20th-century intellectual giant and one of the most influential writers of his day, brings together his legendary broadcast talks during World War II in which he set out to "explain and defend the belief that has been common to nearly all Christians at all times." Mere Christianity provides an unequaled opportunity for believers and nonbelievers alike to hear a powerful, rational case for the Christian faith.