this can be either the old or new testament gods, and this is assuming that nothing caused by either side happened earlier(i.e. genesis), this is also under the assumption that this is the forgotten realms but i'm willing to see perspectives of other worlds(also this isn't for gameplay, this is just the lore)

In FR, the "overgod" Lord Ao (as in alpha and omega, get it?) already fills the role of the all-powerful bearded guy who only shows up from time to time. If he were outright replaced by plain old Yahweh... No clue, or should I say God knows. 🙃 Maybe he would want worship from mortals, unlike Ao who specifically demands that prayers be directed to the rest of the pantheon instead, while allowing the "Unholy Trinity"(some variation of Lucifer, Satan and Beelzebub?) to tempt and torment mortals as a test of faith.

i could definitely see lucifer, satan, and beelzebub as the unholy trinity but the post originally had the dragon(satan), the beast of the sea(the antichrist), and the beast of the earth(the false prophet) in mind