Part of the problem, at least how it appeared to me, was that McGrath just wasn't aggressive enough in his response. In other words I don't think that Christianity offers no response, but McGrath wasn't assertive enough to put it out there. It is like the times I have watched my oldest nephew play soccer. His problem isn't that he lacks the skill or the athletic ability, but that he lacks the aggression to get in there in mix it up.
This lack of aggression really showed itself in one key part of the debate when McGrath really could have reversed things and helped us see that the fact that Hitchens says religion is evil and poisons everything is evidence that God exists.
During the question and answer time the first question is directed at Hitchens. The question is: If God does not exist on what basis can anyone say this action is right or this action is wrong? In his response Hitchens eludes the question, instead he focuses on how the religion gives people the divine permission to do evil things. Yet the question remains: Why does he consider these actions evil? What is his basis for declaring them so?
I agree that with many of the things that he deemed evil that have been done, and are being done, in the name of religion (other points I think he misrepresents what the Bible says and Christian theology). For me this gift of morality, the ability to speak of something as right and wrong, is a gift from God confirmed by His Word. But why would Hitchens speak of things of being right or wrong/good or evil?
This is exactly the point C. S. Lewis begins Mere Christianity with. Lewis closes chapter one by writing:
"These, then, are the two points I wanted to make. First, that human beings, all over the earth, have this curious idea that they ought to behave in a certain way, and cannot really get rid of it. Secondly, that they do not in fact behave in that way. They know the Law of Nature, they break it. These two facts are the foundation of all clear thinking about ourselves and the universe we live in." (p. 21)
Lewis tells us that people possess this idea of what is right and wrong naturally. It is part of who we are, and that is why Hitchens can look at these things and declare them evil (with the majority of Christians agreeing with him). So while I would appeal to God being the author of this "Law of Nature", how would Hitchens account for it?
I think this is an important question to be asked because it gets to the basis of why we consider things to be right and wrong. How does nature and natural selection account for the morality that we now possess? If God doesn't exist why should I care to live a moral life, what benefit is it to me? Why should I care about atrocities on the other side of the world if they don't affect me? On what basis can you appeal to me to be moral? All questions to be considered if God doesn't exist.