I am neither an atheist nor a Christian...my own upbringing included more Native American beliefs than anything, and I don't identify with any given religion or anti-religion. Frankly, I don't know if God exists or not...and neither does anyone else. That said, nothing could definitively make me believe that God doesn't exist, the same way that nothing could convince me that ghosts or the Nimerigar don't exist, because the absence of evidence does not prove non-existence. For example, if I thoroughly explore the part of the world that I know and have access to, I won't find a shred of evidence that shows giant squids exist...does this mean they don't exist? If there's a way to prove a negative, we have yet to find it. On the same token, I don't know that anything could convince me that God DOES exist, because if someone showed up claiming to be God I'd likely not believe them.