I thoroughly enjoyed and was challenged by Erik Wielenberg's book. As a committed Christian theist, I disagree with the conclusions he draws and the positions he defends, as well as some of his interpretations of what Christian theism is, but I deeply appreciate the clarity of his writing. I also think that he has chosen the proper issues, given the aims and scope of his book. This is a much better work than the widely read books by Dawkins and Hitchens.
My main criticism is that on his form of naturalism, there are some strange or perhaps recalcitrant (for the naturalist) metaphysical entities. For example, he argues that there are necessary ethical truths which are a part of the basic furniture of the universe. The problem is that this perhaps leaves us with a non-physicalist form of naturalism, with something like a Platonic realm of necessary truths that are not physical entities. Others have argued that such truths supervene on the physical, but this is not Wielenberg's view as described in the book. This is important because the theist has a ready explanation for the existence of necessary ethical truths--they are a component of God's character, a necessary ethical Being. Such truths have better metaphysical fit within a theistic universe than a naturalistic one. Even though I had many disagreements with the book, I would recommend it to people on all sides of the God issue, both because of its clarity and salience. For those interested in reading an account from the theistic side, I'd recommend The Recalcitrant Imago Dei: Human Persons and the Failure of Naturalism (Veritas)