The Arithmetic of Grace and the Audacity of Unforgiveness Text: Matthew 18:21-35
Introduction: The Economy of the Kingdom
We live in an age that is simultaneously obsessed with and utterly confused by the concept of forgiveness. On the one hand, our therapeutic culture peddles a cheap, sentimental forgiveness that costs nothing and means nothing. It’s a sort of "I'm okay, you're okay, let's just move on" approach that never actually deals with the sin. On the other hand, we have the unforgiving cancel culture, a digital mob with pitchforks that never forgets, never relents, and offers no path to restoration. Both are grotesque parodies of the real thing.
Into this confusion, Jesus speaks with breathtaking clarity. He does not offer a self-help tip or a gentle suggestion. He provides a non-negotiable, absolute standard for His disciples, and He anchors it in the very fabric of salvation. The parable He tells is not a sweet story for Sunday School children; it is a terrifying warning. It is about the economics of the kingdom of God, an economy that runs entirely on grace. And in this economy, to receive grace and then refuse to extend it is not just rude. It is a capital crime. It is spiritual treason.
Peter comes to Jesus thinking he is being remarkably generous. He is willing to stretch the rabbinic standard of forgiving three times all the way to seven, the number of perfection. He is offering a forgiveness with limits, a forgiveness he can manage and control. Jesus responds by blowing the doors off Peter's entire accounting system. He is not interested in incremental generosity. He is demanding a radical, grace-drenched way of life that mirrors the very heart of God. What follows is a story designed to rearrange our moral furniture, to make us gasp at the debt we have been forgiven, and to tremble at the consequences of withholding that same forgiveness from others.
We must understand that this is not a lesson on how to earn our salvation by forgiving. That would be to turn the gospel on its head. Rather, this is a lesson on the necessary, inevitable fruit of a heart that has truly understood its own salvation. An unforgiving Christian is a contradiction in terms, like a square circle or a hot iceberg. It reveals a fundamental misunderstanding of the gospel itself. If you get the gospel, you give the gospel. If you get forgiveness, you give forgiveness.
The Text
Then Peter came and said to Him, “Lord, how often shall my brother sin against me and I forgive him? Up to seven times?” Jesus said to him, “I do not say to you, up to seven times, but up to seventy times seven. For this reason the kingdom of heaven may be compared to a king who wished to settle accounts with his slaves. When he had begun to settle them, one who owed him ten thousand talents was brought to him. But since he did not have the means to repay, his lord commanded him to be sold, along with his wife and children and all that he had, and repayment to be made. Therefore, the slave fell to the ground and was prostrating himself before him, saying, ‘Have patience with me and I will repay you everything.’ And feeling compassion, the lord of that slave released him and forgave him the debt. But that slave went out and found one of his fellow slaves who owed him one hundred denarii; and he seized him and began to choke him, saying, ‘Pay back what you owe.’ So, his fellow slave fell to the ground and was pleading with him, saying, ‘Have patience with me and I will repay you.’ But he was unwilling and went and threw him in prison until he should pay back what was owed. So, when his fellow slaves saw what had happened, they were deeply grieved and came and reported to their lord all that had happened. Then summoning him, his lord said to him, ‘You wicked slave, I forgave you all that debt because you pleaded with me. Should you not also have had mercy on your fellow slave, in the same way that I had mercy on you?’ And his lord, moved with anger, handed him over to the torturers until he should repay all that was owed him. My heavenly Father will also do the same to you, if each of you does not forgive his brother from your hearts.”
(Matthew 18:21-35 LSB)
Calculated Mercy vs. Boundless Grace (vv. 21-22)
We begin with Peter's question, which sets the stage for the whole discourse.
"Then Peter came and said to Him, 'Lord, how often shall my brother sin against me and I forgive him? Up to seven times?' Jesus said to him, 'I do not say to you, up to seven times, but up to seventy times seven.'" (Matthew 18:21-22)
Peter, bless his heart, is trying to be a good student. He's heard Jesus' teaching on reconciliation earlier in the chapter. He knows forgiveness is important. The rabbis taught that you should forgive someone three times. After the fourth offense, you were off the hook. Peter, feeling expansive and spiritual, more than doubles the going rate and suggests seven. Seven is the number of completion, of perfection. He thinks he is being extravagant.
But Peter is still thinking in terms of bookkeeping. He wants a forgiveness ledger. He's asking, "What's the limit? When can I righteously stop forgiving and start punching?" He wants to know the point at which grace expires and he can revert to good old-fashioned score-keeping.
Jesus' answer is designed to shatter this whole mindset. "Seventy times seven." Now, some translations have "seventy-seven times." It doesn't matter which you pick. The point is not to get out your calculator and start a tally sheet for your annoying brother-in-law. Jesus is not replacing Peter's small number with a bigger, but still finite, number. He is using a figure of speech to signify a number that is boundless, limitless, and uncountable. He is telling Peter to stop counting altogether. The forgiveness you extend is not to be measured. It is to be a disposition, a way of life, a constant flow. Why? Because it is a reflection of the forgiveness you have received.
An Unpayable Debt (vv. 23-27)
To drive the point home, Jesus tells a parable. The kingdom of heaven, He says, operates on a certain financial principle.
"For this reason the kingdom of heaven may be compared to a king who wished to settle accounts with his slaves... one who owed him ten thousand talents was brought to him." (Matthew 18:23-24)
The numbers here are intentionally hyperbolic. A talent was the largest unit of currency, equivalent to about 6,000 denarii. A denarius was a day's wage for a common laborer. So one talent was roughly twenty years of labor. This man owes ten thousand talents. This is a debt that is beyond astronomical. It would be billions of dollars in today's money. It was more than the entire annual tax revenue of a large province like Galilee. This is not a debt you get into by being a little careless with your credit card. This is a debt of cosmic proportions. This is the point. The debt is utterly, hopelessly, laughably unpayable.
This is the debt of our sin before a holy God. Every sin we commit is an act of high treason against the infinite King of the universe. We don't just owe Him a little something; we owe Him everything, and our debt is beyond our ability to even comprehend, let alone repay.
The consequences are severe: the man, his family, and all his possessions are to be sold. This was the law of the day. It wouldn't come close to covering the debt, but it was the just penalty. The man is bankrupt, and judgment is coming. He does what any desperate man would do. He falls on his face and begs for time. "Have patience with me and I will repay you everything." This is a pathetic, impossible promise. He can't repay it. He's just stalling. But in his plea, the king is moved with compassion. And what the king does next is shocking. He doesn't just give him an extension. He doesn't set up a payment plan. "And feeling compassion, the lord of that slave released him and forgave him the debt." The entire, unthinkable, unpayable debt is wiped out. Canceled. Forgiven. This is grace. It is unearned, undeserved, and radical.
The Audacity of Unforgiveness (vv. 28-30)
The scene that follows is one of the most jarring in all of Scripture. The man who has just been forgiven an infinite debt goes out and demonstrates that the grace he received has not penetrated his heart in the slightest.
"But that slave went out and found one of his fellow slaves who owed him one hundred denarii; and he seized him and began to choke him, saying, ‘Pay back what you owe.’" (Matthew 18:28)
The contrast is staggering. Ten thousand talents versus one hundred denarii. The second debt is not nothing, it was about three or four months' wages. But compared to the first debt, it is less than a rounding error. It is pocket lint. And look at the man's reaction. He doesn't just ask for his money. He seizes his fellow slave, physically assaults him, and chokes him. He is violent and merciless.
The irony is thick enough to cut with a knife. The fellow slave falls down and uses the exact same words the first man used to the king: "Have patience with me and I will repay you." In this case, the promise was actually plausible. A man could conceivably pay back a hundred denarii. But the forgiven slave "was unwilling." He refuses the same plea for mercy that he himself had made moments before. He has his fellow slave thrown into debtor's prison.
This is a picture of the Christian who has been washed in the blood of Christ, forgiven a debt that would have damned him for eternity, who then turns around and harbors bitterness, holds a grudge, and refuses to forgive his brother for some petty offense. It is monstrous. It is wicked. It shows that he has no true grasp of the grace he claims to have received. He treats the cross as a get-out-of-hell-free card for himself, but then insists on strict, merciless justice for everyone else.
The Reinstatement of Debt (vv. 31-35)
The story concludes with a chilling warning. The man's hypocrisy does not go unnoticed.
"So, when his fellow slaves saw what had happened, they were deeply grieved and came and reported to their lord all that had happened... And his lord, moved with anger, handed him over to the torturers until he should repay all that was owed him." (Matthew 18:31, 34)
The other servants are rightly appalled. They see the injustice and report it to the king. The king summons the wicked slave. Notice the king's argument. It is an argument from grace. "I forgave you all that debt... Should you not also have had mercy on your fellow slave, in the same way that I had mercy on you?" The logic is inescapable. The grace you received should have become the grace you gave. Because it did not, the king's compassion turns to righteous anger. The pardon is revoked. The original, unpayable debt is reinstated, and the man is handed over to the torturers until he can pay it all, which is to say, forever.
Jesus then drops the hammer. This is not just a story. "My heavenly Father will also do the same to you, if each of you does not forgive his brother from your hearts." This is one of the most sobering verses in the Bible. It tells us that our forgiveness of others is not optional. It is the acid test of whether we have truly received God's forgiveness. If we refuse to forgive others, we are providing exhibit A in the courtroom of heaven that we have never truly understood or embraced the grace of God in Christ. The unforgiving heart is an unregenerate heart.
This does not mean our forgiveness earns God's forgiveness. That is works righteousness. It means that a heart that has been truly transformed by God's grace will, necessarily, be a forgiving heart. It is the evidence, the fruit, the proof. As we pray in the Lord's prayer, "forgive us our debts, as we forgive our debtors." The "as" there is not one of equivalence in earning, but of correspondence in character. We are asking God to forgive us in the same way that we, as forgiven people, now forgive others.
"My heavenly Father will also do the same to you, if each of you does not forgive his brother from your hearts." (Matthew 18:35)
And notice the final phrase: "from your hearts." This is not about mechanically mouthing the words "I forgive you" while inwardly seething and plotting your revenge. This is about a deep, genuine, heart-level release of the debt. It is a promise not to bring it up again, not to gossip about it, not to hold it over the person's head. It is a commitment to treat the sin as paid for by the blood of Jesus, just as God treats our sins.
Living in Light of the Canceled Debt
So what does this mean for us? It means we must constantly be doing the arithmetic of grace. When someone sins against you, before you do anything else, you must stop and look at the cross. You must look at the ten thousand talent debt that God forgave you for Christ's sake. You must see the bill for all your sin, past, present, and future, and see the words "Paid in Full" written over it in the blood of the Lamb.
When you are steeped in that reality, when you are overwhelmed by the magnitude of your own forgiveness, the hundred denarii debt someone else owes you is put in its proper perspective. It shrinks to its actual, insignificant size. How can you, who have been forgiven billions, choke your brother for a hundred bucks?
This is why bitterness and a critical spirit are so spiritually lethal. They are symptoms of gospel-amnesia. They are the actions of a man who has forgotten he was cleansed from his old sins. An unforgiving spirit is a proclamation that you believe your brother's sin against you is a greater offense than your sin against God. And that is a blasphemous lie.
Therefore, we are called to be conduits of grace. God's forgiveness flows to us, and it must flow through us. If we dam it up with bitterness and unforgiveness, the flow stops, and we show ourselves to be wicked slaves, fit only for the torturers. But if we let it flow freely, forgiving as we have been forgiven, we show ourselves to be true sons of the King, citizens of a kingdom built entirely on the glorious, scandalous, and liberating economy of grace.