Keep in mind that the AT Forums are still intended to be technical forums first and foremost. I make that distinction because what you propose would not only expand our non-technical offerings, but it would require a very heavy-handed level of moderation that we (as volunteers) are not equipped to offer. And in lieu of that, the new subforum would just have the same level of quarreling you're already seeing.
Ultimately the purpose of most of our social subforums are to get stupid topics out of OT. P&N exists to get the political trolls out of OT (and that's where religion should be too) and L&R is to get the sexually frustrated nerds out of OT before they can make fools of themselves (to be recorded by Google for all-time). The only practical reason for creating a religion forum would be to explicitly get it out of OT; it's not causing a problem so that shouldn't be necessary.