I see what you mean.
I can't say that you are wrong though. I think that the show has evidence to support us both. I'll stick with my interpretation because it makes me happier.
Though... Touga's monologue
(name correct?) about sin (at the well) makes a bit more sense when viewed your way... So perhaps a bit more of the evidence is on your side... Perhaps I saw it the way I did because I don't think like a Christian. The point about needing to ask for help to escape sin totally went over my head.