The diety fades away in part because of the concept of infinity, that being, if the diety created the universe, who created the diety? However, the same concept of infinity raises the same question of where did all the energy/matter in the universe/multiverse come from?
...where did all the energy/matter in the universe/multiverse come from?
Ex nihilo. If nothingness is unstable, there is a non-zero (albeit terrifyingly miniscule) probability for a patch of negative pressure energy to come into being; once that happens, the process of inflation gets underway and extends to spatial infinity and towards temporal (future, at least) eternity, giving birth to infinitely many bubble universes along the way.