oneGod,
I don't know if this has been said already, but couldn't God have used those pagan stories as some sort of sign of things to come? The fact that stories like that had been around before does not prove that Christianity is invalid. After all, you don't see any people believeing those religions any more, do you? Christianity has grown SO MUCH throughout time. That must be a sign to you that there must have been some validity to the resurrectuion.