There is a verse that says "I tell you these things before they happen, so when they do happen, you may believe." The particular verse escapes me right now, but that's the purpose of prophecy.
So the fact that he made predictions and then told us when they come true it will prove his existence somehow proves his existence?
That doesn't even make sense.
I predict that sometime in the future the oceans will swell and consume the great states of california and florida. I predict great wars in the middle east and I predict the rise of a great nation in the orient. When this occurs you will know that Ape City is the one and true god and you must put a dollar in the box!
Seriously check out a comparison of Jesus and Horus....it's really crazy how many times this story has been flipped around and had the names changed but it's always the same. Put a dollar in the box...