Depends who you ask, of course. But truth be told, no one really asks this question. Repentance just isn’t thought of as a quality which has shades of meaning; either one repents or one doesn’t, and there is nothing in-between. If there is a debate about repentance, it has to do with its definition. Is it a change of mind, as the etymology of the Greek might indicate (μετά-νοια, after-thought)? Or is it an abrupt and radical break with one’s past, a conscious walking in a new direction entirely? When has “hearty repentance and true faith” occurred? Is it real repentance if one “backslides” into recidivism? Is it possible to repent of something for imperfect reasons? Again, it all depends on who you ask. But these definitional questions function for the sinner as questions of quality. How much is enough to fulfill what constitutes genuine repentance?

Heaven help you if you’re a contrite sinner in need of grace from other sinners. The sinner in need of reconciliation always wonders how much repentance is enough, but can never ask that question out loud; they can never demand grace, lest the dynamics of conditionality, self-justification, and deserving spoil the whole barrel of apples. The one who has come to the end of their rope has no recourse but to appeal for mercy from arbiters of grace. Nevertheless, the sinner can’t help but wonder how much penitence is necessary to satisfy the wrath of those they’ve wronged. It’s not a matter of doing enough good works to earn favor but of the measure of “godly grief” (2 Cor. 7:10). Even to hope for restitution is to transgress this boundary.

Repentance is always some sort of action, regardless of how it’s defined, and the doctrine of repentance is often the precise spot where adherents to justification by faith alone unwittingly sow the weeds of works-righteousness. Appeal is rightly made to the priority of God’s kindness that leads to repentance (Rom. 2:4), but the implications of this text are not often taken seriously. If God’s grace is always prior to human response, then the attitude of the forgiver never changes, no matter how many times the sinner fails to repent. Still, repentance should happen at some point, even after 490 times.

So what does the requisite repentance look like? The etymology of a word is almost never a good measure; meaning is determined by usage. Within the New Testament, the best illustration is to be found in the parable of the prodigal son in Luke 15. Certainly, there are other passages that fit the bill — perhaps Paul’s autobiography in Philippians 3, the entire story of Jonah, or Zacchaeus (Luke 19). But given how prominent repentance is for Luke, the prodigal son is the best place to begin.

The prodigal, after renouncing his family and an undefined period of riotous living, “comes to himself” – something like a waking up from the fog of his nightmare to recognize the destructive path he’s walked. Knowing the just consequences of his actions, he decides to return to his father as a servant. Having already severed his familial ties, this is the best he could hope for. He then rehearses a speech, wherein he confesses his sin against God and his father and accepts responsibility for everything he’s done.

Repentance, then, is the confession of one’s wrongdoing and the avalanche of ruin it created. It is a place of utter powerlessness, embracing the mercilessness of the worldly consequences of sin and subjecting oneself to the justifiable wrath of the those you’ve wronged. For the repentant sinner, there are no excuses, explanations, or rationalizations. The suddenness of the prodigal’s decision is also notable. He is not mired in self-examination but responds out of desperation. As Luther rightly notes, “If you wait until you are sufficiently contrite, you will never get to the hearing of gladness” (LW, Vol. 12, p. 370).

But as is often noted, something unexpected happens when the prodigal returns home. He is embraced and kissed by his exuberant father. He gives the speech of repentance he has practiced, but the father takes no notice of it. Celebration ensues. The bombshell of grace in this story is that the father’s actions seem to circumvent his son’s repentance entirely. How much repentance was enough for the father? It was enough for him that the son came back at all.

For the father of the prodigal, there is no measuring of his son’s repentance. There is no suspicion of its authenticity. There is no cross-examination. There is no fear of backsliding. The father does not question where all the money went or what it was spent on. If he mistrusts his son, he doesn’t show it. He doesn’t wonder whether his son has duplicitous motives for returning. Perhaps the son is just trying to save his own skin (he is!). Though the father holds all the cards, so to speak, there is only joy at his son’s return, irrespective of why he returned at all. It seems that the father is so eager to forgive the son that he will take whatever he can get.

The father’s response to the prodigal contrasts sharply with that of the other brother to provide a model of forgiveness. This is the real point of the parable, told by Jesus to the grumbling Pharisees and scribes. If the father has received the prodigal back as a son, the brother refuses to acknowledge any restored relationship, calling him “this son of yours.” The father’s forgiveness is a negligent act of injustice to the brother — and that’s really the point. As much as the parable is an analogy for the ministry of Jesus, it is told so that his unforgiving Jewish brethren might repent of their un-forgiveness.

Wherever one places the bar for what constitutes genuine repentance, it should undoubtedly be lower. In practice, the greater and more egregious the sin, the lower the bar should be. However the sinner returns, whatever reasons motivate their return, and regardless of the depth of their transgression, these things do not matter one iota to the forgiving father. There are no probing questions to be asked of the one who returns or “holding their feet to the fire”. To those whose lives are governed by right and wrong, action/consequence, and getting what one deserves, this kind of forgiveness invariably appears unjust and even reckless.

Perhaps the kind of forgiveness Jesus describes is impractical, if not impossible. God might have a no-questions-asked return policy, but can we really afford such a risk? It may sound reasonable to withhold trust and create exceptions to the rule of forgiveness—but only if one never actually needs forgiveness, to say nothing of the parable of the unforgiving servant in Matthew 18. It also assumes that our lives are a closed-system and fails to appreciate the generative power God’s forgiveness of us can have. Heaven help us to forgive as we have been forgiven (Mt. 6:12)!

How much repentance is enough? For the sinner, it’s whatever is needed or demanded of them, however outrageous it may seem. But for those who have been wronged, this question has no real place in the economy of forgiveness. For them, repentance is not something that can be precisely outlined, lest it become a casuistic escape hatch to elide Jesus’ 70×7 directive. There is no place for deliberation over the quality of repentance, only a joyful eagerness to forgive. The more the offended tries to identify someone’s “true” repentance, the less their forgiveness looks like “true” forgiveness.