Person 1 (P1) and Person 2 (P2):
P1: do you believe in god?
P2: there's no evidence of him - why should I?
P1: *thinking* well, can I say something that might make you reconsider that?
P1: if I told you that I didn't exist, would you believe me?
P2: of course not! I can see you here, it'd be stupid to say you don't exist.
P1: and if I leave to get a drink, would you still think I exist?
P2: well, yes. I've seen you before and you'd probably tell me that you've gone for a drink.
P1: what if I didn't tell you?
P2: *thinks* I might think you've gone missing, but I've seen you, so I'd know you exist.
P1: what if I'm in a room with no windows, and I'm calling for you, but you can't hear me. Would you believe I exist, and would you think I'm there?
P2: If I can hear you, I would.
P1: what if I was somewhere halfway across the world, and you've never met me before in your life. Would you think I exist then?
P2:since I've never met you, no.
P1: Do you believe there is a god?
P1: well, what if you haven't met him yet? What if he's trying to constantly reveal himself to you, shouting, but you keep pushing him to the back of your mind? what if he's across the world now, and now's not your time? wouldn't it be, then, foolish to say that God isn't real?
P2: *stays silent*