Since it's live...
The Bible is used, hence Christianity and the references, mainly because it's such an old and mysterious text, and 80% or better of the world's population can relate to it in some way. Using Catholicism derivatives gives the whole thing an "ancient" feel. I myself have used religious/Christian references in stories and such in both positive and negative manners. That, and the words are a lot easier to find than just hashing something up, it gives it a more solid base.