Although I'm not a religious person this movie uses the bible in a very realistic manner. For better or for worst religion gives hope to many people and gives them something to put meaning towards.
This idea of having the right words to let people live in a world without anything except faith is capitalized.
Both the protagonist and antagonist view the book as importance but for different reasons. Gary Oldman's character sees it as a way to gain power while Denzel Washington's views it as a necessity for getting the world back from the brink of extinction.
Amazing movie and my favorite live action film of all time, highly recommended.