“There is proof against that theory, if you consider the Bible to be proof. The Bible posits God as not merely a superior being, but as The Superior Being who is all-knowing, all-powerful and eternal. It does talk about angels, but I don’t think that is what you mean.
Regarding an ET (extra-terrestrial):
Even if such a being did exist (i.e., a being higher in intelligence than us, who came from another galaxy, etc.), there would still be some fundamental issues left unsolved.
Namely, something must be eternal. If there was ever a time when there was absolutely nothing, there would still be absolutely nothing now — which is not the case, for something exists now.
Also, the “something” that is eternal must have a will. This Eternal Something must have willed the existence of something other than itself. It alone was eternal and could have remained that way. Therefore, having a will, the Eternal Something is personal, i.e., an Eternal Someone.
A being who was merely more advanced than us, from another galaxy, yet finite, would not be the Eternal Someone. The Eternal Someone is infinite with regard to time and space. It doesn’t sound like ET is that.
So even if there were a higher being from another galaxy, the existence of such a being would not speak to nor solve the problem and/or mystery of the Eternal Someone. In other words, a being from a superior race would just mean we have to go back to the drawing board again. If they’re not infinite and eternal, we’re still in a quandary over who is.
We have a couple of articles that speak to this subject. See Nothing (www.everystudent.com/journeys/nothing.html).
Some people point out ETs as a way of forestalling the larger question of what we on earth must do concerning God. But even if ETs did exist, that wouldn’t — at all — change what’s happening here on earth. With or without ETs, we’re still finite beings who must answer to an infinite Being. And the same would be the case for those ETs. They would be accountable to an Almighty God just as we are.