No...for the same reason that newborns are - probably - not theists, nor atheists, nor agnostics. *** You have to have learned or imagined for yourself the concept of "deity" and formed an opinion on the existence of deity before you can be any of those things. *** Now: I could be wrong. It might be that, even without having been taught the concept of deity, I might have conceived such a thing by myself. But I suspect not since it is in some ways a somewhat advanced concept. I may be a little inventive with practical things, but with philosophical things? Naw. That isn't me. Similarly: I probably would have never invented "I think, therefore I am" or "all that exists must have an origin", or even something as fundamental (in philosophy) as a hypothetical "First Cause". etc. My inventiveness, I think, simply does not run in that direction.

the Aboriginals were here for 60 thousand years why did they not know of god until whiteman told them about this god?

I would. Just like Moses before he came to know God, he was hopeless and at a breaking point when he was forced into exile from Egypt. Without hope, life doesn't seem to make sense or even when it seems void of any meaning at all. So there has to be something that can help us know our purpose again.

No. You can't believe in something that you are unaware of. On that note, I might add that almost every culture believes in a higher being of some kind. The laws that regulate behavior in these cultures are based on those handed down by this higher deity and go back to the garden of Eden.

Same reason the idea exists in the first place, everything has an origin.As I understand it was the Mesopotamians who first wrote about another race coming to their planet, that had magical abilities, so something happened to those people for them stories to exist, civilization sprung up in this area, prior to that we were hunter gatherers, and in the Bible you have Cain the farmer, and Abel the shepherd, you have Cain leaving to build the first city. His offspring were blacksmiths, craftsman, etc, same as the Mesopotamian story which states the gods brought Me's to their land, ie kingship, priesthood, swordsmanship, farming, make-up etc. The Ethopian Bibles still have the stories of the fallen angels coming to earth and giving mankind much the same thing, this is merely hinted at in the Bible. Even to this day the Lucis trust believes that Lucifer was the saviour of mankind and fell to save them from the demiurge, this is sponsored by the United Nations. John Dee had a scrying ball with Lucifer on it, and to this day with the likes of Madam Blavatsky, Alice Bailey, Aliester(Edward) Crowley have influenced today's society, the gnostics believed Lucifer to be androgenous along with Adam, and they believe in Solve and congradula, the mixing if opposites, hence transgenderism, non binary all this stuff we see happening in society is to strip away Christianity, The secret doctrine by Madam Blavatsky which was said to influence Hitler. Alan Watts, Aldous Huxley, George Orwell, Then going back to Darwin, going back through Francis Bacon to Nietzsche, to John Dee, Plato and Socrates, it's this same alchemist mysticism.