While this show is founded on a concept which I find irresitably appealing (Christians and non-Christians in conversation and debate), I've found myself generally critical of the show for failing to achieve intellectual and airtime balance between the unbelieving guest and the apologist(s) for religion. This episode is a happy exception, in which both debaters are equally bright and articulate. I definitely recommend this episode, if not the entire podcast.
Alister McGrath defends the ideas he has published in Why God Won't Go Away while Stephen Law assures that McGrath has to put up a geniune defense. They also manage to agree on some key propositions about how discourse and debate ought to be conducted. They also go back and forth a bit on theodicy and the problem of evil, which is clearly one of Law's pet arguments.
There is a fantastic bit around half an hour into the show when Law poses the following question, "What it is, actually, that the Holy Inquisition, Hitler, Stalin, Mao, Pol Pot, all had in common?" Well, that is something to chew on.