I don't believe in god. I don't like to believe, I like to know. Why are we, non believers, always trying to explain why such a thing like god does not exist? The burden of the proof should be on believers, who brought this up, to explain how god exist. but they never do. When a believer asks me why I don't believe, I just answer him/her, why do you believe. I then let them struggle trying to explain the non sense.
I can only speak from a personal stand point but I don't spend/waste time trying to explain why a god doesn't exist. My default is he/she/it doesn't exist therefore the people who do believe can spend time trying to prove the unprovable. As you say, the burden of proof is down to them, I have nothing (literally) to prove
Good answer! I avoid religious people and ignore them or change the subject if they bring up anything to do with religion, but that's a great retort I might use instead.