Imagine that God exists. I’m convinced he, she or It doesn’t, but let’s speculate…
Picture this: God is standing at the end of time (and that's where he must be). He has just experienced the entire universe from A to Z.
He didn't create the universe, but was just one of many forces being born into it. The "omnipotence", his boundless might, came later. He rose to the occasion, through many tough battles with various opponents, to emerge victorious.
So what does he do now?
He travels back in time to ensure that everything happens exactly as he remembers it, of course, to ensure that he indeed will become the most powerful entity in the universe.
Or perhaps he does want to change things. He's not happy with how things are and who he has become. But no matter what he does he's just ensuring that what happened comes to pass... again. He is unable to change anything.
A mass slaughter in the Andromeda Galaxy, the Holocaust, all the wars, all the suffering, all the horrible incidents are necessary to make the universe... what it is.
He's in a prison, a nightmare beyond comprehension, and can't get out.
So he becomes the christian Lucifer, rebelling at creation, knowing fully well that everything he does has already happened.
He has already seen it from the other side. That whatever he sets in motion, even though seemingly unknown to him will turn out to become something Known.