@ jcl:
Your proof is no valid proof. You can say that gods (/tooth fairys/unicorns) existence is very very unlikely. But this wont make it a proof.
Example:
Your first proof:
Experience is limited to a certain amount of time, it is theoretically possible that you (or whatever) just missed the day when god was doing something. And if god is omnipotent he maybe made everyone forget for some reason.
You must not confuse a proof in mathematics, and a proof in natural science. Only in mathematics you can really prove something. In natural science you can only assign more or less likeliness to a theory, based on certain criteria. One of them is experience, i.e. observation.
All pigs we've seen so far walk on the ground and don't have wings, thus we assume that pigs don't fly. Theoretically it's possible that there is a flying pig with wings that we just haven't seen yet, or have forgotten for some reason. In that sense, there is no mathematical proof that pigs don't fly. We just consider it extremely unlikely, based on our experience. It's the same with the existence of the Christian God.
