Today (July 7, 2012) marks the 60th anniversary of the publication of the landmark book Mere Christianity by C.S. Lewis. Of course, this is an unusual anniversary because, it's not really a "book" in one sense of the word, but it is a collection of three previously published books. Add to this, the fact that those books were collections of previous radio broadcasts over the BBC before they were published!
This book, Mere Christianity, has been transformational to so many.