This post is related to this other post What should I do about a religious player who refuses to accept the existence of multiple gods in D&D?
Alot of people were saying maybe RPGs just aren’t for this guy that wanted one god and to deny the existence of other gods in the rpg world. If this is a problem for the current group then he could find another group with other christian nerds. I have DMed a game where all the players and their characters followed Christ. I set it medieval europe. Many of the bad guys were demons, devils, undead, etc. But I also had enemies that followed other real world religions or other branches of Christianity. At the end of the day RPGs are not Real, they are just personalized storytelling and wish fulfillment; does it matter if the paladin kills a cleric of the wildmother or a pictish Druid/priest?