Abraham was getting on in years, and his wife Sarah was pretty old too. It looked as if they weren't going to be able to have any children, which was a big disappointment. Then the Angel of the Lord told Abraham that he was going to be the father of a great nation, despite his advanced age. Sarah laughed at this, but sure enough, she became pregnant with Isaac.
Now, Isaac was obviously pretty important to Abraham, and an integral part of God's promise to him. So it was no small request when God asked Abraham to take Isaac up the mountain and sacrifice him. He obediently took up his knife, and prepared to gut his son right there on the altar. This is taken as a sign of Abraham's great faith in God.
(Nota bene: Clearly, the Abraham in the story was suffering from some sort of delusional state, possibly paranoid schizophrenia. Hearing voices telling you to kill someone is mental illness, not visitation from God. But in the context of the Genesis narrative, it supposedly was God talking, and I'm going to assume that to be the case for the sake of the theological argument, notwithstanding the more realistic psychiatric interpretation of the event.)
So let's apply this parable to the modern Christian (or Muslim or Jew, or anyone who takes a book to be divinely authoritative). The Bible (or Koran) represents God's promise to the believer, a divine revelation about the nature of the universe and man's place in it, and how to obtain eternal reward, just as Isaac was the embodiment of God's promise to Abraham. If you believe that the Book was a divine gift to humanity, then you might well treat it as especially precious, just as Abraham must have felt about Isaac.
Now suppose God appears to you and tells you something that contradicts the Bible. Which do you believe, God or the Bible?
Most Christians I ask this question chuckle and say it's a meaningless hypothetical, because God would never contradict Himself. Stop to parse that one out logically: I describe a scenario where God contradicts the Bible, and they respond He'd never contradict Himself. Does that not imply that they assume the Bible = God?
When I point that, they usually admit that of course God is not a piece of text, but the Supreme Being and Creator of the Universe, which clearly this bound stack of papers on my desk cannot be. But they still insist that since the Bible is the Word of God, and God does not lie, He would never contradict His own word.
Yet logically, it still reduces to the same thing: they make the Bible text absolute and binding upon what God can and can't do. In other words, although they tried to evade the choice I presented them with (God or the Bible, and the Bible itself says you cannot serve two masters: Matthew 6:24), they've made it: To them, the Bible, and not God, is supreme.
That's not what Abraham did. He could have reasoned, "Wait a minute. God promised to make me a great nation, and this is my only son, the son God Himself gave me, the son through which my great nation will come to be. God wouldn't break His promise. Whoever this is asking me to sacrifice Isaac, it can't be God!" But he didn't do that. He took up his knife, and obediently prepared to sacrifice his son. To repudiate God's gift to him.
You see, Abraham placed his faith in God, not in God's gift to him. He didn't necessarily know how God could keep His promise after Isaac was ashes, but he didn't need to: he trusted that God was God and that meant God could do anything He damn well wanted.
In the same way, I think Bible-worshippers would do well to take their faith away from the Bible, and place it in God directly. If God wants to contradict the Bible, He certainly can; He's not obliged to conform to any text, especially not one that has been through so many fallible human writers, redactors, translators and interpreters. (And how is worshipping the Bible not a violation of the commandment against graven images, anyway? Why is worshipping a textual depiction okay, but a graphic depiction isn't? Aren't they both the wrong thing to be worshiping?)
Now, there's a happy ending here, just as there was (sort of) for Abraham and Isaac. If you are truly willing to cast your Bible into the sacrificial flame, to give it up completely and affirm that God and God alone is Supreme, you'll find out that you don't actually need to sacrifice it. You can keep it, and read it, and derive whatever meaning and value you can from it. But it will become a book about God, perhaps a deeply treasured book, but still just a book, and not God. Read it, interpret it, re-interpret it, criticize it, love it, hate it. Just don't worship it.