The inquisitor does indeed defend himself in that way, but it needn't imply that he's not so satanic. The devil could out-argue any of us, if he were real. That was his primary job as God's tempter. He makes the best case possible for the wrong views, to tempt us into sin.

But there's a difference between atheism and anti-theism. The devil and his minions, including the inquisitor, would be anti-theists in that they'd reject what they know to be true. The inquisitor criticizes God's plan for our salvation, but that must be futile because as the creator of everything, God would have the right to do whatever he wants with Creation. The inquisitor, then, must be deceiving himself, and I think that's what Jesus senses in the poem when he kisses him. It's a condescending reaction. He's saying implicitly to the inquisitor, "There, there. We both know you just need a hug."

The root of that problem in the narrative is that Dostoevsky is only pretending to be an atheist. He's trying to criticize religion, and of course he does a remarkable job for someone who's a believer. But he is a Christian believer.

The question, though, is the same one raised by Sartre in "The Flies." Would it be alright for God to toy with his free creatures? If we created an artificial intelligence, would we have the right to torture or enslave it? Do we have the right to abuse our children? The answer seems to be no, but that's largely because we're not fully divine. We have godlike power but not godlike wisdom. We're supposed to trust God's intentions in addition to fearing his power.

But the more we have to trust in what seems wrongheaded, the more we might just be victims of a cult mentality. We might suspect, then, that we're being conned, in which case perhaps there's no God and no divine plan.

If Jesus did return, one question I'd ask him is what I present in this article on how the Romans humiliated the Jews. Was Jesus content with being crucified? Was his trust in God vindicated by the religion that spread in his name? Was he just grasping at straws in the face of the effective Roman falsification of monotheism?

The discussion between Paul and Jesus in "The Last Temptation of Christ" is relevant here too.

I think the Jewishness of early Christianity necessarily fell by the wayside because of Rome's destruction of Jerusalem and its humiliation of that religion. Jewish myths, morality, and monotheism had to be Hellenized to be attractive after the Jewish-Roman wars.