This right here is what makes it roleplaying.
You as the player know what to do to move the story forward. Just need to figure out how the character you built would go from Point A to Point B, then roleplay doing it, even if it means they bumble their way through it like a clown.
Let the DM worry about what skills you need, if you even need them at all; the only thing the player has to do is describe their actions and their intentions.
A good DM will make sure you fail forward.
I mean, technically he is just a lich… Who so happens to have a cult that worships him, which somehow gave his incorporeal spirit power during his short absence after the defeat at the hands of his right-hand lieutenant, Kas, and has absorbed the power of a lesser deity to use as his own while escaping from imprisonment by the Lady of Pain for a failed plot to usurp the cosmic order when he infiltrated Sigil, the City of Doors.
So, not a god, just a lich with the power of a God.
Haha petty semantics!