Punishment, I repeat, is not the thing required of God, but the absolute destruction of sin. What better is the world, what better is the sinner, what better is God, what better is the truth, that the sinner should suffer — continue suffering to all eternity? Would there be less sin in the universe? Would there be any making-up for sin? Would it show God justified in doing what he knew would bring sin into the world, justified in making creatures he knew would sin? What setting-right would come of the sinner’s suffering? If justice demanded it, if suffering be the equivalent for sin, then the sinner must suffer, and God is bound to exact his suffering, and not pardon; and so the making of man was a tyrannical deed, a creative cruelty. But grant that the sinner has deserved to suffer, no amount of suffering is any atonement for his sin. To suffer to all eternity could not make up for one unjust word.
An unjust word is an eternally evil thing; nothing but God in my heart can cleanse me from the evil that uttered it. But it does not follow that I saw the evil of what I did so perfectly that eternal punishment for it would be just. Sorrow and confession and self-abasing love will make up for the evil word; suffering will not. For evil in the abstract, nothing can be done. It is eternally evil. But I may be saved from it by learning to loathe it, to hate it, to shrink from it with an eternal avoidance. The only vengeance worth having on sin is to make the sinner himself its executioner.
— George MacDonald, Unspoken Sermons, Third Series, “Justice,” quoted in Discovering the Character of God, p. 259