Disproving the christian (and muslim) god

[GrandizerII]

It doesn't matter that logically one would assume the natural order to have been one god (monotheism) and gradually many (polytheism).  Religious history shows that prior to the monotheistic Judeo-christian religions, animism and paganism saw spirits and gods, plural, in nature.  Heck, even the Greek, Roman, and Egyptian pantheon predate monotheism.

That's nonsense because plenty of native American tribes were every bit monotheists

https://en.wikipedia.org/wiki/Great_Spirit

The Great Spirit, known as Wakan Tanka among the Sioux, Gitche Manitou in Algonquian, and in many Native American and First Nation cultures as The Creator, is the supreme being, God, or a conception of universal spiritual force.

This isn't a good example of strict monotheism (see Hinduism/Brahmanism for a similar sort of theistic belief). And the historical facts, overall, are clear. The trend was from polytheism to monotheism, not the other way around. So your faith-derived "theory" regarding the evolution of theistic beliefs is misguided.

Oh, really. You should ask the Jews to see if that's true.

Where do you think the concept of "Messiah" came from? Not to mention the old testament is clear the Messiah would be rejected.

“The stone which the builders rejected has become the chief cornerstone. This was the LORD's doing; it is marvelous in our eyes.” (Psalm 118:22-23)

The Old Testament makes no prediction that the Messiah would be born of a virgin woman, be crucified for our sins, and then rise from the dead three days later. If you don't believe me, again, ask the Jews. They would know the Tanakh better than you do.