I am creating a campaign world that is supposed to be a “refuge from the gods”: no true deities can come here, no intervention in the affairs of mortals. People came here from the Forgotten Realms to escape domination by the gods.
The problem I'm running into is that, after reading the Forgotten Realms wiki entry on deities, I am a little confused about the line between "god" and "very powerful entities and creatures". What categorically differentiates "gods" proper in the Forgotten Realms Cosmology from other very powerful beings (for example primordials)? What can Gods do that other beings can't?
More background
I have already done some extensive work on this project. Much of the world’s history and lore revolve around a number of lesser primordials that came to this world to escape the jealous gods that tried to exterminate their kind in the early days of the formation of the multiverse. Many humanoids came here as well, mostly to escape wrathful gods on their own worlds.
Over time, the inhabitants of this world started to worship other things: fey and elemental spirits, dragons and other powerful creatures, and the country-sized primordials that walk along the surface of their planet. These creatures are powerful, and can do favors for their followers, but none of them can do anything close to a Wish: they can’t magically smite a mortal dead on the spot without actually being there to hit them with something, they can’t create new races of people from nothing, can’t oblige an entire race of people to give up their free will and stay evil for all time. They aren’t true gods.
I want very badly for this world to exist in the same multiverse, with the same lore and logic as the Forgotten Realms. For example, the goblinoid races of my world are all descendants of goblins, orcs, and hobgoblins that escaped the Forgotten Realms so that they could have the freedom to be “good”, now that they are no longer under the thumb of their evil gods. Followers of Maglubiyet visit my world from the Forgotten Realm to hunt down the ancestors of these original goblinoids, punishing goblins with Barghests etc. The feywild is also a very different place: without deities in charge of the winter and summer courts, the split between seelie and unseelie is a little more complicated.
Problem restated
I want to keep cosmology compatibility with the Forgotten Realms so that my world can be populated by refugees from the Realms, but I’ve become unsure which entities would exist in my world, and which would be banished by the anti-god property.
I'm not sure how can I draw a line between god (not allowed in my world) and not-god (allowed in my world) that would exclude Maglubiyet, Lathander, Gruumsh, and Torm (and also Titania and the Queen of Air and Darkness if possible), but also include primordials, fey spirits, and powerful magical creatures that characters could obtain divine magical abilities from.
Let me be clear that I am not just looking for a source of power for users of divine magic. I am trying to resolve a lore-continuity problem in the world I've created. My players are going to want to know what types of entities divine magic users can follow - I want to provide them a very clear-cut rule of what is and what isn't a god so that they can choose a source of power with clarity.