interesting, had a Jesus like prophet shown up in all world cultures, spouting the same message, I think that would have gone a long way to proving a likely god. If Myans were told don't cut out hearts to make the rain come, just pray to the all loving all caring god, if they were told about original sin, the coming of a savior, the origins of the universe, and a big flood where 8 people hopped on an impossibly big wood boat with all flora and fauna aboard. If that story had been told to all cultures around the time of moses and then a savior showed up preaching the peace and love god, I might believe.
There simply is no worldly explanation the bible appearing all around the world prior to world travel.
If you take the bible as presented and the timelines as gospel, I can not see how all cultures so quickly went from knowing god existed to polytheistic pagan gods. As egypt was rising and their dog headed gods appeared, some of the Great great great great great grand dad patriarchs were still living to tell great great great great grand kids that their gods were bullshit.
You can say that this is addressed by the Moses story where they started looking to the polytheistic gods just days and weeks after being delivered. First off I don't buy that, but even if I cede the point that people can quickly revert to old religions, I am not sure that you can create new ones on the heels of people actually walking and talking with god.