In my main series, I intend on introducing a cult that is an offshoot of a notorious midwestern Christian religion. I'm not sure how far I should go in explaining the roots of the cult and how its policies are tied to that religion, or if I should even mention the ties at all.
You're the artist. You can do whatever you want, up to and including total polemic critique of said religion. However, being a Christian myself, I can't say that I won't think your book is total crap and not read it after dropping you a one star. Just being honest, lol. Now, that being said, if the "religion in question" is actually a cult, there's a tasteful way of handling this. You can fictionalize a lot of it, or make up an entirely different religion. In Far Cry 5, the whole game is about a Christian-like cult, but the creators did a good job, since one of the characters is the pastor of a church, and he denounces the cultists as being false, so if you want to not offend, there are ways you can do that. In the game the cultists don't even use the bible, they have their own book. So they're not Christians. If your aim is in fact to offend, that's another matter. And again, as the artist, I think you have the right to offend. I believe that. It might not be tasteful, though, lol. Then again, a thoughtful critique, even if wrong, isn't necessarily distasteful either.
So I think your treatment of the subject matter will depend on whether or not its distasteful. It will also depend on whose reading.
So you're talkin' about Moromonism, aincha? lol