Maybe this will shut creationists up finally

[Cecelia]

I know this for sure. If God did come down and wasn't exactly how they think he should be, then they'll just call him a fake. This is how much they have convinced themselves of who or what God is or should be.

This is exactly why Atheists win Pascal's Wager.

Let's say someone appears out of nowhere and claims they are god.  They provide evidence for their miraculous powers.  Atheists would be skeptical of course, but they'd be open to this God being God.  Christians would outright deny him if he contradicted their god (which is basically just the bible)

God: I can prove I'm god!  THE BIBLE SAYS I'M GOD!  I INSPIRED THAT BOOK YOU KNOW!
Christians: OHH!  AHH!!
Atheists: Uh yeah... going to need more than that.

God: I can prove I'm god.  Boom.  World hunger gone.  People no longer have a need to eat at all.  Also as a favor, I removed that pesky appendix everyone has and assigned any purposes it had to another organ.  I also cured all diseases.  Now to answer all the questions... No all religions aren't true.  Judaism is barbaric, and I'm ashamed that the people I created stoned people for all sorts of things including homosexuality, and working on Sunday.  They dismissed Science, when evolution was the best explanation for how people came to be.  Adam and Eve is made up story like the rest.  No, I didn't come down here born as a virgin and sacrifice myself to myself to change my own rules. Don't be silly. And I certainly never wanted anyone to fly planes into buildings. And an elephant? Really? Don't get me started on L. Ron Hubbard. Everybody has been fooled.  I'd have come down earlier, but I'm not actually omniscient.  I walk away for a few million years, waiting for evolution to occur naturally, and then come back and see this?  Seriously.  Stop hating each other.  Oh and I'll give you Superman and The Doctor as real people.  That should keep things safe for a while.  Now I'm off to my Q:ZD tee time with Cthulhu. 
Atheists: Hmm... maybe he's just an alien messing with us, but the claims are at least worth looking into.
Christians: DEMON!  DEVIL!  THE REAL GOD IS NOTHING LIKE THIS FRAUD!