Let me start by saying that I'm not religious at all. I think I was baptized a Protestant, but...
The way I understand it, the only really important thing in the Bible for Christians is the New Testament. That's where Jesus shows up, and that's where God stops smiting people. Here you get an expansion on the 10 commandments (only important thing in OT in my opinion) that adds a sense of morality and loving your neighbor. But if you really want to be a good Christian, you don't need a Bible. You need to help other people. Brighten up someone's day. Not punch that asshole in the face. Not killing or stealing. Am I a good Christian? By these guidelines, I think so.
Now what I mean by the OT being "unimportant" is that it doesn't have much bearing on how to be a good Christian besides the 10 commandments. I very much doubt that many Christians follow the exhaustive rules laid out in leviticus.
Just an opinion from an atheist.
