Richard Dawkins comments on the God Delusion here.
1. The question of primacy - There's a huge difference between saying the existence of God (being the greater issue) has significant implication in the area of science (along with others area) or that science is a field where the existence of God can be looked at ... and stating the existence of God is a scientific question. Dawkin's statement falsely presupposes the supremacy of science over God whereby it denies the definition of God. Rather than getting the cart before the horse, Dawkins errs in setting the physical over the spiritual.
2. The question of justification - Dawkins continues to suggest that God's law has been given such that men may "try to please God" by obedience to his law. Here, Dawkins, while he seeks to set himself as an expert on the very Scripture he sets out to deny, shows his lack biblical and spiritual understanding resulting from both his ignorance of the Christian faith and his faulty exegesis of the biblical text. The Christian position is that "faith" not "works" serves as the instrument of justification. It's no wonder that if Dawkins misunderstands this (a central truth associated with the Bible/gospel) that his understanding and view of much of the rest of Scripture is twisted.
3. The question of existence - Dawkins states that apart from the existence of God the world "stats with essentially nothing and builds up" to what we find today with all the complexities, etc. What does Dawkins mean my "essentially nothing"? Is that to suggest either: (1) that there was even minimalistically something... & if so, where did that come from???; or (2) it began with nothing... & somehow something came and grew from nothing, i.e., life from no life, intellegence from no intelligence, law from nothing, etc.?
4. The question of ethics/morality - Dawkins does two things:
a. In suggesting that a person can be "good" apart from the existence of God, he fails to speak to (and provide answers) to the basis, standard, and meaning of "good".
b. While Dawkins uses comparison, it's clear that atheist's do not consider "fear of punishment" as a legitimate motivation for obedience. While I agree there are better motivations, that does not deny "fear" as a legitimate motivation.