Well, the Christians stole a lot of things from the pagans in order to try to get them to convert. Most major Christian holidays were derived from pagan rituals. It wouldn't surprise me if church traditions are also derived somewhat from paganism.
Yes, I do remember that now, because he sacrificed himself for the sins of humanity, thus in that service giving the people the bread and the wine would, in my mind, symbolize the rebirth of his sacrifice to rid those people of their sins? I don't exactly remember what the Big Guy said.
Personally, I think all religions are wrong.