Was thinking about this at work the other day while listening to Chariots of the Gods by Erich von Daniken.
Would all religions unite now it was proven their was only one God? How would the Atheists react? It's actually quite hard to imagine how the world would change, because you have no idea how people are going to take the news.
Would people STILL not believe? Would seeing and hearing not be enough for some people? Would the billions of people who now believe in him, refuse to worship him due to resentment? (Not saving their loved ones, etc).
How many wars would break out determining to fight for his honour even though he does not ask for it?
Questions are endless, but what do you think?