As I recall, in the movie "The Day After Tomorrow," a group of people is attempting to survive a period of intense cold in the NY Public Library. Naturally, they start burning books to keep warm. The atheist character ultimately consigns Nietzsche to the flames - perhaps the last surviving copies of Nietzsche's work. Shockingly, he retains a Gutenberg Bible - because it represents the dawn of the age of reason.

I think the point is obvious. If all of Western Civilization were to be suddenly destroyed, what ONE THING would you choose to save? With the Bible, you could rebuild all the rest.

The King James Bible stands as perhaps the most influential version of the Bible, and thus is one of the most important bases of Western Civ.

[In response to the comment "I'd save an Encyclopedia":]

An encyclopedia won't help you develop the belief that time is linear, that the universe was created by a rational being and therefore can be rationally studied, or that a man has unalienable rights. It also won't inspire Handel's Messiah or the ceiling of the Sistine Chapel. The list goes on.

Plus, they won't let you bring the entire set of encylopedias on the evac helicopter!