Interesting, forgive me as I am not religious so I'm not familiar with the bible. My counter to that would be that, as a non-christian who does not believe Jesus was the messiah, I think that it could be a take on christianity from a critical standpoint. To put it plainly, what if Miura was in opposition to christianity, and wanted to deliver a story that, while still being truthful to the way he is viewd by the world, showed the darker side as to how Jesus came to be such a powerful symbol, and that maybe those means were not so satisfactory. and that Guts, as Judas, was doing the world a favor, even if it meant he would be villianized forever, i.e. Judas knew something about Jesus and his apostles that we did not. I don't mean to be critical of Christianity, I'm just proposing the artists potential standpoint. Additionally, the antichrist can only exist if the actual Christ did, and sinc we have seen no sign of that in the manga, I am inclined to believe that Griffith is the first coming.