Personally, I would do nothing. I would probably say "oh, okay then" and then get on with my day (such as it is). I would instantly stop being an atheist, because the theist burden of proof will have been met, but otherwise? Who cares?
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'
