For years, psychologists have assured us that the desire for revenge, like other forms of aggression, is hardwired in the human psyche. When someone hurts us, the lesser angels of our nature urge us on to anger, resentment, and to hurt our tormenter back.

But recently, psychologist Michael E. McCullough of the University of Miami has revealed that just as deeply rooted as vengeance is the impulse to forgive.

Eva Kor, 81 years old, is someone who has done the unthinkable. She is a survivor of the Auschwitz death camp, a victim who, with her twin sister Miriam, endured Dr. Josef Mengele’s inhuman medical experiments. Her father and mother and two older sisters were murdered in the gas chambers. Yet Eva has publically, emphatically forgiven the war criminals who caused her unimaginable pain. She even gave a friendly embrace to Oskar Groening, now 94 years old, a former SS sergeant who has been found guilty of being complicit in the deaths of 300,000 people.

Not everyone admires Eva for her stand, including her husband, Michael, a survivor of Buchenwald, who has stated flat-out that he will never forgive any Nazi for what they did to him, his family, and countless other victims. Furthermore, 49 Holocaust survivors have signed a protest, criticizing Eva for what she has said and done. But Eva has an answer for that. She told reporter Joe Shute of The Telegraph (UK), “Why survive at all if you want to be is sad, angry and hurting? That is so foreign to who I am. I don’t understand why the world is so much more willing to accept lashing out in anger rather than embracing friendship and humanity.”

It took Eva years to arrive at the point where she could let go of her anger and hatred. For survivors and their families especially, but even for so many others who know about the Holocaust only through books and documentaries, Eva’s decision is unimaginable. But she says that since she has removed rancor from her heart, she has been at peace.

On January 10, 2017 Detective Steven McDonald died at age 59. McDonald was a fourth-generation New York City cop.

In September 1986, McDonald had only two years on the police force. He and his wife, Patti Ann, were expecting their first child. On a hot afternoon, he and his partner were working undercover in Central Park, investigating a rash of stolen bicycles. They spotted three teenage suspects near the park’s boathouse. As the police officers approached, McDonald noticed that one of the teenagers, Shavod Jones, 15 years old, had a bulge in one of his socks. McDonald ordered the teenager to show him what he was concealing. Jones pulled out a Saturday Night Special and fired three shots at McDonald. All three .22-caliber bullets struck the young cop: one lodged above his eye, another pierced his throat, and a third shattered into fragments that embedded themselves in McDonald’s spinal column. At the hospital, doctors gave Patti Ann McDonald the sad news that there was nothing they could do for her husband, that he was paralyzed from the neck down, and to breath he would be on a respirator for the rest of his life.

McDonald spent months recuperating at Bellevue Hospital. When his son Conor was born, the baby was baptized in the hospital chapel so McDonald could attend the ceremony. From his sickbed, McDonald issued a statement that astonished the city: he forgave Shavod Jones. “I feel sorry for him,” McDonald said. “I forgive him and hope that he can find peace and purpose in his life.”

As a juvenile offender, Shavod was given a relatively light sentence—3½ to 10 years in prison. He proved to be a troublesome inmate, who spent 8 ½ years behind bars, much of it solitary. Three days after he was released on parole, and before McDonald could meet with him as he had planned to do for years, Jones was killed in a motorcycle accident in East Harlem, his old neighborhood.

Once he was out of the hospital, McDonald met with Jones’ mother and attended church services with his grandmother. Then he took his message of forgiveness to the world, traveling to such war-ravaged, hate-filled hot spots as Northern Ireland, Bosnia, and the Middle East.

During his remaining 30 years, in his private life, McDonald was a devoted husband and father. He was tremendously proud when, in 2010, his son Conor joined the NYPD. In 2016 Conor was promoted to sergeant.

In addition to his family, McDonald was committed to his faith. When he heard of the death of the hero-cop, Cardinal Timothy Dolan, archbishop of New York, hailed McDonald as “an icon of mercy and forgiveness… a shining example of the best of what the New York Police Department represents, a loving husband and father, and a fervent and faithful Catholic.”

After McDonald breathed his last, his father, retired NYPD cop David McDonald, stepped out of the room and found the corridor packed with police officers. “I can’t believe how many lives he touched,” McDonald senior said to reporters from The New York Post. “So many people came up to me these last few days and told me stories about him and what he did for them.”

A little farther back in time is the case of St. John Gualbert (c.993-1073). He is not a well-known saint, although he is popular in his hometown, the lovely Italian city of Florence.

John was the younger son of an aristocratic family. He grew up to be an arrogant, thoughtless, short-tempered young man. He was perhaps in his late teens or early twenties when his elder brother was murdered. Understandably, the family was devastated; in his grief, John’s father made him swear that he would hunt down the murderer and kill him. John took the oath gladly.

On Good Friday, as he was walking through Florence, John spotted his brother’s killer. At the same moment, the killer saw John, and fled. John ran after him. After a long chase through the city streets they came face to face at the end of a narrow dead-end alley. There was no place for the terrified man to run. As John drew his sword and stepped forward the murderer dropped to knees, flung out his arms in the shape of a cross, and commended his soul to God.

John may not have been the best Catholic in the world, but for a man of the eleventh century it was impossible to ignore the significance of the moment. It was Good Friday, and John was about to take revenge on a man who was frightened, defenseless, penitent, and had assumed the image of the crucified Christ. That was too much, even for a man as worldly as John Gualbert. He sheathed his sword, forgave the murderer, then walked to the hilltop abbey church of San Miniato to thank God that His grace had stopped him before he committed such a terrible sin.

In the story of St. John we have a vivid example of a life-altering change of heart. We don’t know how long he had hunted for his brother’s killer, how long he had nurtured his murderous hate. We do know that at the moment when he was prepared to commit murder himself, the unexpected reminder of Christ’s sacrifice on the cross touched his heart and changed his life. It could not have been easy returning home that day and telling his father that he had met his brother’s murderer and had let the man live.

Lent is coming. For 40 days, millions of Christians across the globe will perform acts of penance and charity, and intensify their prayers, imploring God for forgiveness. Integral to those prayers and good works is extending forgiveness to those who have injured us. Eva Kor, Steven McDonald, and John Gualbert showed mercy to those who, from the perspective of pure justice, did not deserve it. Their example leaves us awestruck, not to mention humbled.