Necromancy is fine with Christians when their God does it, but evil when other gods do it. The Abrahamic god is the god that conquers all other gods, stealing their power for himself and turning them into his servants. Then the asshole encourages his followers to turn against each other so they have more motivation to keep him central to their lives.

Gods in general aren’t really necessary anymore, but they’re kind of like meta organisms, quasi living things. They fights back against threats to their own existence, encouraging humanity to remain subservient instead of recognizing our true place as the highest authority.