"Prove to me god doesn't exist"

[drfuzzy]

I never make the assertion that a god doesn't exist, I simply ask them how they know.

Atheism isn't the assertion that a god doesn't exist, it's a disbelief one does.

The only problem with asking them how they know is that you have to listen to all of the inane answers.  
"I have a personal relationship with god!"  
"I can feel him in my heart!"
"God speaks to me, I can feel him when I pray."
"God exists, the Bible says so!"
"How can you look around at this beautiful world and not know that god exists?"
"I had an experience (healing, revelation, vision, saved from disaster, NDE, having the leaves blown out of my yard, etc.,) that convinced me that god exists."
"Every time I'm around my sainted ______ I see god in them."
"When I pray (for rain, to find my car keys, to get a job) it usually happens."
- - - And a dozen other equally ridiculous, un-provable gobs of woo.