It might be that, as spirit of the dead re-incarnates in people and uses them to complete their missions, so it is that the spirit of God was re-incarnated in Jesus Christ to save the world from perishing.
As mythical stories are of the great heroes of the past, and their statutes were erected or mould in their remembrance, it might be so too that God once lived on earth and might then be a great hero of his people.
He might have promised people existing with Him then, that His spirit will continue to live and guard their ways.
Could these be the basis of the argument about God's existence; does God really exist or not? Or could it have been from the observations of the first humans, of the connection between the main man and the mind man, which speaks to the main man in most of his ponderings, worries and decision making time? I mean those first humans might have concluded that since there was no other man around him during his thinking, then, the mind man must be a spirit; that knows him but which he does not know or see. Maybe 'God the Spirit'.
Since oral tradition authentically whiles away with time; that is. Some facts are left unpassed from generation to generations. The facts about the time of the existence of God might have been left unpassed to the times when the arguments about the existence of God occurred. Confusion of different details about Him would have come up since that was millions of years back.
In the African context, there is the belief about the existence of the divinities with the Supreme Being, these divinities might definitely be those, who in the Book of Genesis, God was calling on, saying, "come, and let us make man in our own image, after our likeness". Gen. 1:26.
Before the creation, God must have been dwelling somewhere on earth with these divinities, this I inferred from the book of Genesis 1:2, "the earth was without form and void, and the spirit of God was hovering over the face of the waters", water, from which He later called out the dried earth.
It is really true that God created earth but not without help, in fact, He did cal people to come so they could work together to create man in their own likeness, so, Obatala, Esu, Sango, Ogun (all these are gods/divinities in the Yoruba part of Nigeria). Have all these gods/divinities not come to dwell among us and even in our own likeness?
There had been no story likened to that creation story of Odua, where he descended from heaven with a pigeon and some sand to begin the spreading of that place now called earth, he must have been on God's errand since he is a divinity among the Africans, and a representative of God in nature's designing.
Thus, African which is said to be the first place where man existed could as well be the place where the spirit of God first hovered over the surface of water and where man was been created until they begin to spread out.
I do not wish at all, to bring forth any theory from these because, our God is unsearchable. I only put down things that cross and entwined themselves on my mind while going through the Bible and some extra-biblical materials.