Well he would have to prove it to everybody for it to be considered evidence, but of course, only a fool would refute such evidence. But the last thing I would do would become Christian. Christianity is a sick cult. A divine creator would look nothing like the God of the bible. It would look nothing like any of religions concepts of it.
That question will remain a hypothetical, as we all know God isn't showing up any time soon. 
I once had a class during highschool regarding something similar to this.
The teacher posed the following question/task: Imagine an alien, and write or draw what you'd think it would look like.
Ofcourse everyone started jotting down some lines here and there, drawing faces, mouths, eyes. Or simply writing down characteristics of what they thought aliens would have. (I believe I drew a circle or something of the sort).
Now the point of this exercise was to think outside of the box, and ofcourse we all failed horribly. Because while we all imagined aliens; these were nothing more than accumulations of expectations we'd have of such a creature. And they all turned out to have human features one or the other.
The thing is, it is so easy to imagine things. To adhere your expectations, your fears, your wants to figmants of the imagination. Is it any wonder 'the Son of God' appeared before us as a man? Considering the patriarchic structure at the time? Is it any wonder that followers of a believe, a figmant of the imagination, think that they are right? That they will be saved? That something out there cares about their existence at all? A divine purpose even? But in one way or another always benefits them over another?
The truth is that the exercise I had in highschool never had any right answer, we cannot imagine alien life nor can exclude the possibility of it being out there. Hell, we might be the excrement of aliens, but we just haven't got the knowledge or the capacity of self-realisation. To discuss the existence or absence of an-and-any God as such is utterly pointless.
Man of Steel, I am happy for you if you feel your belief adds something to your life.
I am content with my life in the absence of such rather deterministic beliefs.
I do, however, take offense to your mentality that somehow you will be 'saved', and others will not.
Not because it impacts me in any way, but simply because it's a very child-like assumption from which point all chance of reasoning seizes.