missyjack had a really interesting counter-take on this, saying that the episode was a metaphor for Christian dominance in the US. Personally, I don't think that's what was going on at all - I don't trust SPN to do anything that interesting anymore - and I think this is an interesting but resistant reading.

(Note: a lot of the comments say "people who don't think SPN is awesome all the time are DUMB" - I recommend avoiding them!)