Earlier quoted context omitted.
There's an interesting philosophical line of thought that distinguishes between things that are necessary and things that are contingent. A necessary thing must exist; it can't not exist. A contingent thing may exist, or it may not. In the classical definition of God, he has no beginning or end. He was not created by some other force. He exists necessarily. He just _is_. In fact, many theists describe God using terms…
Why is God a necessary thing?
But binary Truth is so Platonic. I believe there are universes in our multiverse of possible universes where there is an entity that is better than the best entity possible in our universe (no, I do not think that God can bend the laws of Physics and make an immovable object). Also, God is a gradient, since He manifests in people and nature. God as a force of external Good, may be nearly non-existent in times of human war. Nature is more abundant in some places than others.
Finally, more Jungian psychological: It does not matter whether God exists or not exists, what matters is that we keep talking about God. And humans keep modeling the Universe including a God entity. Therefor God is a necessary outcome of human cognitive modeling. We do not have direct access to the physical universe, only to our mental world models, the ontology question becomes irrelevant, what remains is the models. And there, a category error seems plausible: The most capable of Gods, would be capable of evil too, superseding the only-good God. Just like its human modelers are. Just like the old Testament God was good for the chosen people, but evil to the innocent firstborn children of opposing tribes.