Although religious posts aren't included in the rules, they are usually of the same nature. There are grey areas of course, such as the "He is Risen" thread and posts pertaining to wildlife organizations. If you look at the NRA thread in the main forum (it is a locked topic now), you can see things got rather ugly. In the "He is Risen" thread you will notice I had an opinion on the topic, but wasn't going to stir the hornets nest and piss people off. I did have a member PM me out of curiosity though.
My advise, if there is an open thread, and you feel like posting, err on the side of caution.