How to deal with an obnoxious Theology professor?

If it's only him, I'd just attend the class, get the grades, and get out of there. You could also use the opportunity to practice expressing yourself without getting emotional. I'm not accusing you of that -- just saying it's hard to do. If he goes on a tirade against you because of something you said, you can practice giving polite, informative replies without getting emotionally attached to the debate. That is a great skill. What better opportunity to practice it?