I truly do not understand how to interpret your post. The most obvious interpretation to me is that we are free to participate in the game's religion mechanics or not. If it means something else, I'm at a loss.
I think it's the consensus that there are only five distinct religions (i.e., supernatural belief systems) in the game, with one of them being Faithless, which is substantially a "don't care" religion. The other four are Qindred, Virtori, Al'tifala, and Faedin. All but Faithless are strongly associated with specific tribes. Each tribe generally has its own unique flavor of its traditional religion, with the most flavor differences distinguishing the practices and beliefs of the three Faedin tribes -- Brudvir, Kypiq, and Janoa.
There is also some consensus that a cult could attract an NPC following if it is close enough to the beliefs and practices of one of the standard religions. How much of a variation would be tolerable is up to players to find out, so far as we know. There are a number of players who will try to find out -- in other words, stretch beliefs and practices until their congregations lose NPC adherents.