I thought at the time that it was odd that these devout believers could be so ignorant about the foundations of their own religion, but since then I've found it to be common.
A Christian blogger asked yesterday Why do we read the Bible? You can read about her reasons at that link.
I'm re-reading it to re-visit the seeds of my atheism; most Christians presumably read it because a) they're told to or b) they want to reaffirm their faith. They regard the Bible as a book with answers. I'm incapable of thinking about the Bible as a benign, enlightening, or uplifting book, but hey, maybe after I re-read it this time, I'll change my mind.