This is chapter contains much detail on the scholarly analysis of the Old Testament. Much of what Mr. Al-Kadhi writes is accurate, but he unfortunately embellishes his argument from time to time. For instance, Harold Bloom did not "prove" that a woman wrote much of the Old Testament - it is merely a theory, and one that has not won wide support.
However, Al-Kadhi is correct in saying that the four-source theory of the books of Moses is widely (though not universally) accepted by scholars, and that most of the later books of history also show evidence of an editor drawing on two or more sources.
But so what? Isn't that how historians always work? All that happened was that, for many books of the Old Testament, a final editor used earlier sources. What's so unusual about that?
But, I hear you say, the "Books of Moses" were meant to be written by Moses. To which I reply: that is only TRADITION. The BIBLE never says that these books were written by Moses. It only calls them the "Books of Moses" - in other words, the books ABOUT Moses, not by him.
But then you might say: if we do not know who the author was, how do we know they are God-inspired Scripture? The answer is simple: Jesus accepted them. For the Christian, our faith is in the person of Jesus, not the book of the Bible. Jesus accepted the Old Testament as God-inspired. So so do we.
Now don't be misled when Al-Kadhi writes, "Indeed, we can even find Jesus (pbuh) himself bearing witness in the Bible against the Jews that they had changed the commands and doctrines of God and substituted them with their own doctrines... (he then quotes Matthew 15:1-9, Matthew 23:1-33).
If you re-read those passages closely, you will find that Jesus was not accusing the Pharisees of altering the Scriptures. He was accusing them of adding their own traditions to the scriptures. In other words, the Scriptures (the Old Testament) were faithfully preserved, but the Pharisees were being denounced for having an extra set of traditions apart from the Scriptures. (Much as some Muslim sects denounce Sunni Muslims for having the Sunna as well as the Qur'an).
So the authorship of the Old Testament is really no problem at all for the informed Christian. I think Muslims have difficulty because they are used to the idea that Scripture is dictated directly from God. But that is not how Christians understand how Scripture was authored. We believe that the authors used the normal means of writing - which, in the case of history writing, included using other written sources - but that God inspired and guided them as they did it.
More on the topic of "Bible corruption"
The Rebuttal to "What Did Jesus Really Say?"
Answering Islam Home Page