That is an interesting view of it. I mentioned this elsewhere but I happen to share a religion with dostoevsky so this idea is familiar to me and no longer jarring. It does violate a certain idea of fairness or consequence that most people subscribe to, and that contradiction is all over the gospels so it really is one of the original ideas of christianity.

And ultimately this view of repentance is kind of unhelpful in a practical way when dealing with incredibly damaging behavior. We can't really judge the sincerity of someone's repentance, ultimately it is between them and god. We can restrain them from being in a situation where they could commit that act again though, just in case.

Something I think about often is an event that occurred in my home town when I was a young adult. A child, 12 or 13, old enough to know better, was playing with the stove and set the house on fire. One of their siblings died in the fire.

How do you react to that as a parent? You love the child, have to go on raising them. No punishment even makes sense, the idea of taking away the nintendo or whatever is simply grotesque, and what could be accomplished by anything proportional to the consequence? The only thing left is forgiveness. I think this is how it is with god and your hypothetical monster.

* They need suffer only a moment's guilt, before proceeding fearlessly back into the world.

It is not a true repentance if one can wash off their guilt in a moment. True repentance is eternal burn.

> They need suffer only a moment's guilt, before proceeding fearlessly back into the world.

Well, maybe not. Dostoevsky was Orthodox, so I don't know how he would think about this...

From a Catholic perspective sin has both temporal and eternal consequences. God can forgive a truly repentant person any sin, ordinarily through the ministry of the Church by the power and authority of Christ, establishing or returning a person to the life of divine grace in their soul, but the temporal consequences of their sin/s may remain to be repaired.

By analogy, suppose my neighbor became unreasonably angry with me, becoming so incensed that he threw a rock at one of my windows causing it to shatter. Then, after a day of cooling off, he apologized and asked forgiveness. Now suppose I granted him forgiveness, moved by his sincerity and a mutual desire to repair the relationship. The shattered window remains — the glass needs to be cleaned up, and a new window must be purchased and installed. Maybe my neighbor has the resources and skill to do the repair himself; or maybe he can pay directly or reimburse me for contract labor; or maybe he can't afford the repair but promises to pay me back; or maybe one of his family members pays me instead. One way or another, the window will be repaired and my neighbor bears responsibility for it.

So sin, generally, is like this, from the Catholic POV. If the forgiven sinner is not able to make repair before their life ends, then they will suffer in purgatory after death before enjoying the beatific vision. The purification will be more severe depending on the number and gravity of sins. Some mystics claim to have been informed about souls that will suffer in purgatory flames hotter than those of damnation until the last moment before the general judgment, so terrible were their sins and unrepaired consequences of the same.

I'm not sure, I think the strength of his writing isn't well captured in quotes. But it seems like this one resonates with more people than I expected so I concede I was wrong about this.