Who Is God?

Who is God?
That depends on whose mythology you're using.
If you're using the hebreic mythology,then god is YAHWEH or ELOHIM(which is plural,between)
If it is hindu mythology,then it is VISHNU
If it is arabic mythology,then it is ALLAH

And it goes on and on, take the version of your choice.

If you want to stick with the hebreic mythology - which is largely based on the sumerian/babylonian mythology - then the hebreic deity called Yahweh will be your God.

Unless you want to try other versions.

Now the ancient astronaut theory says that the beings we human refer to as gods are highly advanced space travellers from another part of the universe(Aliens,for short),and i don't think that any modern human has ever seen them.

In the sumerian ancient cuneiform texts written on tablet(s) ,these space travellers were the ANNUNAKIs and their leader is who the hebrews later referred to as their god,yahweh.
This is according to the reading of the sumerian tablet by a gentleman scholar called ZACHARIA SITCHIN.