Board Thread:Spoilers!/@comment-4453062-20160217065238/@comment-25926288-20160322023731

Utter solitude wrote: Wow. The Holy Grail is a huge piece of Christian lore.Being married by a bishop absolutely points specifically to Christianity being practiced. People are clearly practicing.

It's a mix of religions, just like real life. I think they are trying to combine several elements. There's a purgatory known as the underworld, a heaven known as Olympus, and a "Hell". That shows a combined effort if there ever was one. The Holy Grail was called "a gift from the Gods" and the Holy grail has roots in Celtic/ Irish mythology.

They likely used bishops because it's more recognizable, but I won;t deny potential monotheism as Lancelot clearly referred to God and they have mentioned religion at times.