The burden of proof realise on the one making the Extraordinarily claim (E.I that a god exist). If i were to claim that i can fly to u randomly the burden of proof would be on me (the one making the extraordinarily claim that i can fly)and when you say "prove to me you can fly the burden of proof is on u cause ur making that ridiculous claim" i would be like you christians and say "NO the burden of proof relise on you because you cannot prove that i cant fly!!" its the same thing with me. you clam something extraordinary, that a god exist, but you cannot prove it. you say that we must prove his existance, which is the same scenario from above.