The Bible is the primary holy text of the Christian religion, and revered by several other faiths. Because this subject is one of the few things likely to seriously offend lots of people if handled improperly, doing missions to Bible fanfic was officially banned after the Department of WhatThe did one.
Yes, there is Bible fanfic. You're welcome.
It is also not unknown for Mary Sue characters to possess, and usually misuse, a Bible. For example, the story of Ariana Alexis Azivedo was a clumsy portrayal of a fundamentalist family's reaction to their daughter attending Hogwarts, and Jackson Earl Simon (NSFW) quoted Genesis (the Biblical book, not the band) at his captives. Even agents who are not particularly religious tend to be annoyed by this.