Tim Stafford is a senior writer for Christianity Today. Among his many books are Knowing the Face of God; As Our Years Increase; The Student Bible (with Philip Yancey); Love, Sex and the Whole Person; Never Mind the Joneses and Surprised by Jesus. He is also the author of a trilogy of historical novels (The Stamp of Glory, Sisters and The Law of Love) which center on many of the reform movements considered in this book. He and his wife, Popie, live in Santa Rosa, California.