The journalist Christopher Hitchens continued his prosecution of an imaginary God last night, in front of almost eight hundred people at Georgetown University. The counts of the indictment were familiar: God is a tyrant, inspiring all manner of evil and holding back the development of the human race. He is not responsible for anything good that any human being has ever done: people knew that murder was wrong before the Ten Commandments were allegedly handed down. He is responsible for "deranged" and "suicidal" doctrines such as that we should love our enemies. Hitchens deems the notion that the torture and killing of Jesus of Nazareth saved humanity barbaric, a reversion to scapegoating and a denial of the personal responsibility of each sinner, and thus of the possibility of morality. Luckily, in the light of modern science we can now see that God's existence is wildly improbable, and only those with a childish need for wish-fulfillment can pretend otherwise.

Anglican theologian Alister McGrath took up the defense. Evils, he pointed out, have been committed in the name of religion and in the name of a great many other things, including such good things as liberty. The safe conclusion is that human nature, not religion, is at the root of human evil. McGrath asserted, in passing, that Hitchens's evolutionary account of morality cannot work. (What McGrath meant, I take it, is that no one can get from the description of how moral instincts came to be to any normative statement about which instincts should be followed and when.) Hitchens, McGrath added, is a man of faith whether or not he realizes it.

As against Hitchens's portrayal of God as a "celestial dictator," McGrath pointed out that God does not compel belief in Him but merely offers His love for the taking. He is a "celestial liberator." Why should Hitchens feel oppressed, McGrath asked, by a Hell in which he does not believe? In seeing him as a dictator to be overthrown, however, Hitchens revealed that wishful thinking works both ways: Many atheists, McGrath averred, want God not to exist because they see Him as the source of constraints they would rather not have.

The debaters often passed each other in the night. McGrath never explained how substitutionary atonement—the notion that Christ died for our sins—is compatible with personal responsibility. Hitchens's explanations, meanwhile, didn't explain anything. Stalin was a type of theocrat, in his view, and Soviet communism a type of faith, and one that could never have succeeded if Russians had not for centuries been conditioned to believe in the divine right of czars to rule them. McGrath did not pounce on this comic circularity. If the putative evil of religion can so easily be detached from monotheism, then perhaps it is, as McGrath said, a propensity in human nature to evil and fanaticism that is to blame; and perhaps Hitchens's version of atheism is not so pure as he supposes.

If you are anything like me, then at a debate you always wish that the fellow on your side had made a few additional points—and if you're the fellow debating, you think of additional points you should have made afterward. Leaning as I did to McGrath's side, I wish that he had challenged Hitchens's planted axioms more forcefully. Hitchens seems to believe that he has scored a telling point against religion by observing that there is no morally good action that a non-religious person could not perform, and no morally good utterance that he could not say. This isn't true, by the way: an unbeliever cannot pray for you, which is a good thing for him to do—and to deny that it is a good thing to pray for others is, again, circular.

But Hitchens is simply wrong to say, as he did, that Christians deny the existence of innate moral instincts. Scripture tells us of the moral law written on our hearts. Christianity does not claim that every moral truth it embraces can be known only by Christians.

The defense of religion is not, finally, important. The debate was titled, "Religion: Poison or Cure?"—a reference to Hitchens's recent bestselling book, God is not Great: How Religion Poisons Everything. But "religion" is neither good nor true, any more than all "alcohol" is tasty; it all depends on what form it takes. Against the particular truth claims of Christianity, which make it good, Hitchens has not dealt a blow.

Hitchens's God is imaginary. Hitchens is right not to believe in this God. Nobody else does, either.

He has been a fellow at the Institute of Economic Affairs in London and has appeared on various television political programs and on numerous radio talk shows. Mr. Ponnuru grew up in Kansas City and went to Princeton University.