Prove to me that God doesn't exist and show your work.
Nickelback, Celine Dion, Avril Lavigne (and that's just Canada).
A bit more serious...
Washington, D.C. Cities that wicked have been routinely destroyed by most deities I can think of. It's amazing how hands-off the almighty powers that be seem to have gotten in their old age. It's a sharp contrast to all the wacky shit that happens in their scriptures.
Then, a huge elephant in the room for me...
Every televangelist and religious huckster that steals and lies in the name of the divine. I can't remember what comedian said it but it was brilliant. "You know, Carrot Top has more say about what people put his name and likeness on than god?"
Finally, there's all the contradictions inherent in faiths of all sorts.
Is this proof definitive? No. Perhaps some higher power(s) existed and did that shit, but I have trouble finding any of them to be omniscient, omnipresent, omnipotent, or anything besides cosmically ambiguous and ambivalent. People have a bad enough time trying to understand other people over gaps as pithy as a few decades. I can't even fathom what it'd be like if you had to hold a conversation with a being of god-like proportions (I guess it'd be like if Q paid you a visit or you found out the Elder Gods were real). I'm 99.9999999% certain that if things like that exist, I'd classify them as "assholes."
To summarize, I can't prove 100% one way or the other. I can, however, take note of abundant circumstantial evidence, apply statistical probabilities, and cover both cases:
1) God doesn't exist ... Dostoevsky's famous quote wins. If I had to place a bet, I'd put it here.
2) Some hypothetical Q-like motherfucker, or more than one, exists and may have played a part in the development of our universe for some reason. If so, I fall back on my instincts and evidence that points to him/them as being agent(s) of assholery.
Diogenes of Sinope: "It is not that I am mad, it is only that my head is different from yours."
Arnold Judas Rimmer, BSC, SSC: "Better dead than smeg."