This book differs from Evidence that Demands a Verdict in that where the first book was simply a collection of notes that brought about evidence that supported the existence and the incarnation of Christ, this book is written more in a traditional form and seeks to undermine two prominent theories, one of them being what is called the source theory (I can't remember the other theory that he attacks in this book, but I think I will spend my time on the Source Theory).
The Source Theory is the idea that the Old Testament was composed during the Babylonian Exile from a number of different sources which includes the Eloist source, the Yawhist source, the Priestly Source, and the redactor. Three of these sources were basically a collection of writings that had come down from pre-exilic period and during the Babylonian exile a person known as the redactor brought these collections together and created the Old Testament as we know it.
I tend to have a more traditional mindset to the construction of the Old Testament than the academics that support the Source Theory, one reason being because a part of me likes the idea that there is a powerful God that can intervene in the world on a miraculous level. Obviously parts of the Old Testament are incredibly offensive to our post-modern society, and I suspect that people want to try to explain these ideas away (such as the wholesale genocide of the Caananite people, which in the end the people of Israel were not able to follow through with). I guess our more scientific minded society that has to weigh all evidence also balks at the idea of unexplainable miracles.
To be honest, the Bible is not the only ancient text in which miracles are recorded, however it is a text that claims authenticity, and also claims to be the truth. It is by making these claims that it opens itself up to criticism, and this I can understand. Many of the other ancient documents are very vague on their miracles, if those miracles happened at all, and can also easily be explained away. However, the Bible calls us to either believe it or not, but because of the difficulties with regards to some of the miracles, we try to water it down so that we can believe it without having to accept the unexplainable events.
With regards to the sources I do partly accept the source theory as it is clear that the book of Genesis has been constructed from numerous sources, and in part, the book of Exodus appears to have a similar construction. I would also not be surprised if parts of the Old Testament were brought together during the Babylonian exile. However, we should note that there are also references to books (such as the book of Jasher) which no longer exist, or if they do exist, they are little more than pious frauds. Mind you, there were a number of books that were written after the exile, so the Old Testament in its final form did not come about until the intertestimonial period.
This brings me to the book of Isaiah. There are a number of academic scholars in Christian institutions who believe that Isaiah is not one but two books. However, they also have a special understanding of what prophecy is about. Their position tends to be that prophecy is God speaking to the people about things that are occurring to them, and either encouraging them or rebuking them. However, as they suggest, prophecy is not about foretelling the future. In a way I agree and I disagree. If God is God then God can tell the future because he can affect the future. For instance (and I am not God so I am bound by the restraints of this world) if I say that on Saturday I am going into the city and I am going to buy a book, am I telling the future, and if I do go into the city of Saturday and buy a book, did my prediction come about? I'm sure if based on that evidence I ran around claiming to be a fortune teller then people would think I was insane. However, from my position and reading of the Old Testament, the future predictions are not fortune telling but rather God saying 'I will do this at a time of my choosing.' If he does do that, well, he is God. The thing with God though is that when he says that he is going to do something well, he does it, it is just that sometimes he takes a lot of time to get around to doing it.