UN-supernatural Christianity?

Talking to a friend the other day our discussion turned to faith. I had heard from a mutual friend that he is a Christian, and he stated that during our conversation. I was a bit stunned though that he also stated he does not believe in the supernatural. When I asked him if he did not find that to be a bit strange, after all Jesus Christ, God, the Holy Spirit, Heaven, angels, etc. are all outside of the realm of our natural world, he informed me he does not take the Bible literally (because it was written by men) and he wanted to discuss the meaning of supernatural. I suggested that he should be lawyer.