I think it's important to understand your faith. As a Christian, since the Bible is so central to our faith, I think it's important to understand where it came from. No, it did not just fall from the sky written on stone tablets.
Jesus Interrupted by Bart Ehrman looks really interesting to me. It's an examination of where the texts that became the New Testament came from. It'll be out in paperback in February. I'm going to pick it up then.