Ignoring religion, there's a possibility "God" was an alien visitor here and there wasn't just one of them!

To simple early humans "they" were certainly Gods who could do amazing things. Those Gods didn't create the Universe, but they may have created homo-sapiens out of mixing "themselves" with early hominids.

It is possible, it also requires a leap of faith but it's as "unprovable" as anything else and is also blessed with some logic.