Not sure if you’ll find this helpful as a starting point for your spiritual explorations, but to the best of my understanding, simulation theory overlaps a bit with certain strains of Buddhism. Ideas like… the physical plane is somewhat illusory; “we” are all interrelated, interdependent fragments of an overarching super-consciousness; we can play as multiple “characters” (i.e., reincarnation); our actions carry a cause-and-effect (i.e., karma); and so on.

Then again, Buddhism is more of a philosophy than a formal “religion,” contrary to popular perception. So if what you’re looking for is something structured and finite, with a universally admired thought leader, then I guess you might have to keep looking for now. ;)

Thanks for the food for thought!