Well, yes and no.

Yes, in that there are three religions and the history is full of wars between them and the Rust Church will persecute Raven Witches, etc.

But all my comments above are my own layering gleaned from what is not said. Like there is a bunch of stuff on the importance of religion…the Psychopomp of the Congregation of the Serpent, the Ferrale of the Rust Church. But there’s no Clerics. There’s no divine magic at all (there are a couple of events that are attributed to miracles, but in a magic rich setting can be lots of other things). So if you’re like me and like to explore “why is that…what could that mean in the fiction” then it’s all there. But you have to find it in the negative spaces.

For instance, the 1200 history of the forbidden Lands, really isn’t. It’s not a history at all really. It’s really the biography of an evil wizard. Everything in there is either prelude for context or historical events that he largely shaped.

So once I detected that, I began to think of the three religions as reflecting 3 different responses to the wizard. The Raven Church are those Zygofer opposed and crushed. The Congregation are those who initially set Zygofer on his path of destruction and then were horrified at how far he took it and tried to reel him in. The Rust Brothers are those who threw in with Zygofer whole heartedly and became him minions. The game doesn’t present them in these terms…but when I read between the lines that’s what I see.

Correlations to modern politics being obvious here. Intentional? Accidental? Or my own baggage coloring what I see. For game juice purposes…doesn’t really matter.

Each of these groups have their own religious flavor…but did those flavors exist from the beginning? Was it really 3 different organized religions who each interacted with Zygofer differently? Or was it just that after 100s of years of magically imposed isolation, each group remembered their past and drew solace and inspiration from it, and turned those memories into a faith that, of course, they believed goes way back…cuz that how churches do it.