>Yes, God is omnipotent and could have stopped it all.

Then he's not omniscient as you implied before. It is a logical impossibility to be both omnipotent and omniscient.

If he's omniscient (All Seeing), therefore he has planned everything in advance. He cannot then change his mind because that would imply a mistake, and that he was not omiscient to begin with. If he does not have the power to change his mind, therefore he's not omnipotent. You can't be both.