I'm curious as to what sort of event or discovery would be enough to "prove" the existence of a god to you?
Would it be hearing the god's voice in your head? Would it be an event predicted in some holy book? The god rearranging the stars of a particular galaxy to spell "Yes I'm real" in every known language, as viewed from Earth?
Well, voices in the head only indicate that you may be insane. If you make enough predictions, one will come true. Proves nothing. Rearranging the stars???---not really because alternate explanations can be offered.
One word... POKEMON!
The main one would be for God to be even a possible concept. However, there's little about the concept of God that squares up with what science tells us about our world and universe. Take away the superpowers and magic and what do you have left?
Any sufficiently advanced technology is indistinguishable from magic.
I'm a skeptic.
Even I don't know what defining evidence it would take for me to reach a new conclusion.
But do you know who would?
An omnipotent deity.
That's the perks of being omnipotent.
They'd know exactly what evidence to present me with, because they would know precisely what I'm thinking at all times.
You don't suppose that IT took one look inside your head and ran screaming to the far corners of the Universe? I'm pretty confident that's what would happen if IT looked inside mine...
Even FSM ain't touching that.
Hearing God's voice in my head wouldn't prove anything aside from the fact that I'm likely a lunatic, as many have no doubt already stated. An event predicted in some sort of holy book wouldn't necessarily prove anything, as such events tend to be vague and open to interpretation. It would literally have to say "Event A is going to happen on day B of Month C of Year D in location E." Now the star thing? That would be nearly impossible to dispute, and thus would certainly make quite an argument for the existence of God.
But so what?
Even if all of these things were to come to pass, which God is it? Regardless of the God, he or she has quite a bit of explaining to do, and merely existing doesn't do anything to garner my worship. For example, the Judeo Christian God (Jaweh, Jehovah, Allah, whatever) is cast in some rather harsh and unpleasant light. The old testaments write him up as a tyrannical monster: brutal, petty, jealous, and cruel, and the new testament isn't much better. Hell or no Hell, such a being would have to alter my entire brain chemistry to make me worship him, and if he did that, then what would be the point?
TL; DR: existence or no, there are few deities that actually merit worship. Existence doesn't necessarily earn them worship, it just means we have to acknowledge them.
A regular chick magnet, that guy.
Actually, if that happened, wouldn't "I must be insane, or maybe someone slipped me some acid" be a much more likely thing to be thinking?
And now I'm going to have to go to a whole lot of trouble to pull off a hoax like that.