What Forgiveness Does to the Body

What's happening

A study published in npj Mental Health Research in March 2026 tracked 207,919 individuals across 23 countries and found that a general tendency to forgive others predicted improvements across 56 measures of well-being, including optimism, life purpose, and relationship satisfaction. The research, led by Harvard's Human Flourishing Program, is the largest longitudinal study of forgiveness ever conducted.

Roughly one in four respondents reported they had "rarely" or "never" forgiven those who hurt them. The most forgiving countries were in Africa, where five of the top six nations ranked highest. The strongest effects appeared in the United States, Japan, and the United Kingdom.

A companion trial involving 4,500 participants across five countries tested a three-hour forgiveness workbook. It produced measurable improvements in anxiety, depression, and overall well-being. Researchers describe forgiveness as an "adaptive coping strategy" that reduces the toxic effects of sustained bitterness on both mind and body.

What the text says

In Matthew 18, Peter asks Jesus a practical question: how many times do I have to forgive someone? Seven seems generous. Jesus answers: seventy times seven. Then he tells a story.

Matthew 18:21-3521Then Peter came and said to him, "Lord, how often shall my brother sin against me, and I forgive him? Until seven times?"22Jesus said to him, "I don't tell you until seven times, but, until seventy times seven.23Therefore the Kingdom of Heaven is like a certain king, who wanted to reconcile accounts with his servants.24When he had begun to reconcile, one was brought to him who owed him ten thousand talents.25But because he couldn't pay, his lord commanded him to be sold, with his wife, his children, and all that he had, and payment to be made.26The servant therefore fell down and kneeled before him, saying, 'Lord, have patience with me, and I will repay you all!'27The lord of that servant, being moved with compassion, released him, and forgave him the debt.28"But that servant went out, and found one of his fellow servants, who owed him one hundred denarii, and he grabbed him, and took him by the throat, saying, 'Pay me what you owe!'29"So his fellow servant fell down at his feet and begged him, saying, 'Have patience with me, and I will repay you!'30He would not, but went and cast him into prison, until he should pay back that which was due.31So when his fellow servants saw what was done, they were exceedingly sorry, and came and told to their lord all that was done.32Then his lord called him in, and said to him, 'You wicked servant! I forgave you all that debt, because you begged me.33Shouldn't you also have had mercy on your fellow servant, even as I had mercy on you?'34His lord was angry, and delivered him to the tormentors, until he should pay all that was due to him.35So my heavenly Father will also do to you, if you don't each forgive your brother from your hearts for his misdeeds."

A servant owes his king ten thousand talents, roughly 200,000 years of wages. An unpayable debt. The king forgives it entirely. The same servant then finds a fellow servant who owes him a hundred denarii, about four months' wages. He grabs him by the throat and has him thrown into prison.

The Greek word for the king's response is orgistheis: a fury so deep it reverses everything. The forgiven debt is reinstated.

The parable's logic is precise. The servant's problem is that he has received something enormous and cannot let it pass through him. The forgiveness stops in his hands. It enters but does not exit. Jesus describes unforgiveness as a kind of blockage: the gift gets trapped inside the recipient, and what was meant to flow becomes a prison.

The Harvard study measured what this blockage costs the body: lower optimism, weaker relationships, diminished sense of purpose. The parable measured what it costs the soul.

The reflection

The study's most striking finding is geographic. The most forgiving populations were in Africa, where communal cultures and religious practice run deep. The least forgiving was Turkey. Forgiveness tracked closely with social cohesion and shared ritual.

Jesus embedded forgiveness into the prayer he taught his followers: "Forgive us our debts, as we also have forgiven our debtors." The grammar is deliberate. The two forgivenesses are linked. One in four people in the study reported they had rarely or never forgiven someone who hurt them. The prayer suggests they are carrying more than they know.