"We all want progress. But progress means getting nearer to the place where you want to be. And if you have taken a wrong turning, then to go forward does not get you any nearer. If you're on the wrong road, progress means doing an about-turn and walking back to the right road; and in that case the man who turns back soonest is the most progressive man."
--C.S. Lewis, Mere Christianity, 1952

I read that book a couple of months ago, and I really enjoyed it. It is a humble, yet persuasive case for Christianity.