I've always considered GOD outside of our 'universe' and any possibility of no longer being God could be a reality in our universe since he is 'outside'. To have a start God would exist outside of space and time to form this universe. Like before 'the beginning'. This could all embody 'simulation universe and many other theories' while remaining true.
God is be beyond logic and understanding in which omnipotent would be best way for use to understand I think.
I think the presocratics had also similar theories about their cosmogony/cosmology.Sounds like Olorun in Yoruba cosmology.
Like some of Parmedines, Heraclit or Platon.
While Parmedines only had some opinion about the cosmogony and no theory, while haveing a theory about cosmology.
I think heraclit did not have a cosmogony but had a theory about cosmology and his "logos".
But Platon definetly described theories about how the cosmos was created.
For example that god created the space, time and matter.
Which implicates that on creating there was no space, time and matter at all.
Meaning that god must have existed outside space, time and matter.
But if I recall correctly then this steps were interpreted in the history as raw schematic because it had few contradictions.