I haven’t yet read the book but am pleased to see that an outline of the book’s argument – "Why I Am Not a Christian" - is now available at the Secular Web’s modern library. It is fairly comprehensive (while still being concise) and is written from the perspective of a former Christian believer who now finds the evidence for and idea of a God lacking. As Loftus puts it
From all of this [examination of claims of the Bible] I conclude that Christianity is a delusion that should be rejected. More specifically, Christianity makes a very large truth claim that cannot be reasonably defended on the basis of the available evidence. In addition, I describe why I am an atheist and what it means to live life without God. My entire case is a fairly comprehensive one, a complete case, from start to finish, from a former insider to the Christian faith.