Paul Farquhar
Legend
The Thuggee where a cult dedicated to the Hindu goddess Kali. They worshipped Kali ahead of all other Hindu gods. But they where still Hindus, not Kali-ists. Kali-ism is not a thing. And there are Hindus who worship Kali who are not Thugs.In the Realms, there are people who are worshipers of a certain deity first, even though they still pay homage to all deities. In any case, when I talked about the Mystran faith, I was referring to her clergy. In the Realms, clerics do, in fact, put their deity above others when it comes to personal importance.
Also, aside from the common rituals&the likes that most cults of the same deity share, examples of how the cult of a certain deity works in different regions are included in the things that I think should be included in such a book (and it was exactly what I meant when I said that the existence of common practices and goals within a faith doesn't exclude particular interpretation of the worship).
Well, if this hypothetical book had an infinite number of pages, I am sure that would be feasible.