Over 55 years since it was first published, C.S. Lewis's wonderful book Mere Christianity still seems to me the best introduction to, and most winsome account of, orthodox Christianity. I've found it surprising that after all these years, there still isn't a real replacement for it. I wrote a little op-ed about this that appeared this morning: here. I'd be interested to hear whether readers agree, and whether there's a book any of you thinks measures up to the Lewis classic.