ROME—As part of his Holy Year of Mercy, Pope Francis on Thursday led over 6,000 priests in a Roman retreat, calling mercy a verb rather than a noun. Priests, he said, have to “show mercy” in order to receive it.

The pontiff offered three meditations to the priests, each one hour long.

During the first session, Francis said he hoped the fruits of this retreat produce a “conversion of our institutional mindset,” because if priests don’t showcase God’s mercy, they become something “bizarre and counterproductive.”

“Nothing unites us to God more than an act of mercy, for it is by mercy that the Lord forgives our sins and gives us the grace to practice acts of mercy in his name,” Francis said.

“Nothing strengthens our faith more than being cleansed of our sins,” he said.

Throughout the day, Francis’ words were deeply rooted in the spiritual exercises of St. Ignatius of Loyola, founder of the Jesuits, the order to which the pontiff himself belongs.

The Holy Year of Mercy called for by Francis began on Dec. 8, and will come to an end on Nov.20. Although he’s asked for the jubilee to be lived throughout the dioceses of the world, several groups had, or still will have, special jubilee celebrations in Rome.

Last weekend, for instance, it was the Jubilee of Deacons, and on September it’ll be the turn for workers and volunteers of Mercy. Their celebration will culminate with the canonization of Mother Teresa on Sept. 4.

Francis kicked off Thursday’s retreat for priests with a meditation on mercy at St. John Lateran Basilica. He then preached a second one in St. Mary Major, and the last in St. Paul Outside the Walls.

Before beginning his first meditation, he offered priests three suggestions.

The first one was for the priests to “begin with what we savor the most and linger there,” because one work of mercy “will lead us to others.” As an example, the pontiff said that “if we begin by thanking the Lord for having wondrously created us and even more wondrously redeemed us, surely this will lead us to a sense of sorrow for our sins.”

“If we start by feeling compassion for the poor and the outcast, surely we will come to realize that we ourselves stand in need of mercy,” he continued.

The second suggestion, he said, is about the way priests speak about mercy.

“By now you have realized that in Spanish I like to use “mercy” as a verb: “We have to ‘show mercy’ [misericordiar] in order to ‘receive mercy’ [ser misericordiados]”.

“We cannot meditate on mercy without it turning into action,” Francis said.

The dialogue each priest has with God, he continued, has to focus on “that sin for which I most need the Lord’s mercy.” And at the outset, “we have to speak of what most moves us, of all those faces that make us want to do something to satisfy their hunger and thirst for God, for justice, for tenderness.”

His last suggestion was for those participating in the retreat to ask for the grace to show and receive mercy.

“We can concentrate on mercy because it is what is most essential and definitive,” he said.

His first meditation, titled “From estrangement to celebration,” turned on the parable of the Good Father — often referred to instead as the parable of the Prodigal Son.

The son who, after spending half of his father wealth, returns “with excessive shame” only to be received “with excessive wealth,” is an example of the “tension” between “our utter shame and our sublime dignity,” because despite being impure, mean and selfish, priests have been called to “distribute the Lord’s multiplied loaves.”

“Only mercy makes this situation bearable,” he continued, because without it priests either believe their own righteousness or shrink to feeling unworthy.

“Mercy is a matter of freedom,” he said. “As a feeling, it wells up spontaneously.”

Francis also told the priests that by saying mercy is “visceral,” it’s not animalistic, because even though some animals may experience something akin to compassion, “like the faithful dog keeping watch at the side of his ailing master,” animals don’t experience “moral mercy.”

He then spoke of a “moral misery,” which comes with the realization that choosing to live without mercy, “to go it alone,” is the wrong choice.

Here he went off the cuff, advising priests to read an encyclical by Pope Pius XII on the Sacred Heart, because “the center of Christ’s heart is the center of mercy.”

Joking, Francis said that at the time it came out, many said the devotion to the Sacred Heart was “a thing for nuns,” to which he responded “perhaps the sisters understand better than we do, because they are mothers in the Church, icons of the Church of Our Lady.”

Repeating a concept he’s used before, the pope also told priests that “mercy exceeds justice” because it brings compassion and leads to involvement.

“The one who shows mercy and the one to whom mercy is shown become equals,” he said.

However, he added, this doesn’t mean that mercy overlooks the objective sin being committed, but that “it takes away evil’s power over the future.” Mercy, Francis said, is not “blind to evil” but actually “sees how short life is and all the good still to be done.”

“That is why it is so important to forgive completely, so that others can look to the future without wasting time on self-recrimination and self-pity over their past mistakes,” he told the priests.

“Ordinary people – sinners, the infirm and those possessed by demons – are immediately raised up by the Lord,” he said towards the end of his first meditation. “He makes them pass from exclusion to full inclusion, from estrangement to embrace. That is the expression: mercy makes us pass ‘from estrangement to celebration’.”

Soon after his first meditation, Francis went to the Basilica of St. Mary Major to address a second group of priests. Before beginning, he took time to present flowers to the Virgin, something he does often in this basilica, such as before and after each international trip.

This time, his remarks were focused on “The Vessel of Mercy.”

The vessel, he said, “is our sin,” like “a leaky bucket” from which “grace quickly drains.” It’s because of this, Francis continued, that Jesus had to teach the apostle Peter to “forgive seventy times seven.”

“God keeps forgiving, even though he sees how hard it is for his grace to take root in the parched and rocky soil of our hearts,” he said. “He never stops sowing his mercy and his forgiveness.”

However, the heart of a priest which has known mercy is no longer a leaky bucket, becoming one capable of being merciful to others: “The best confessors are usually themselves good penitents,” he said, asking the priests to remember their own sins, to find there the ability to forgive.

In this second meditation, Francis spoke of the saints who, throughout history, received mercy. That “isn’t Photoshop,” the pope quipped, but actually “transforms the heart”: From St. Paul to Argentina’s soon-to-be declared saint Blessed José Gabriel del Rosario Brochero.

Paul, he said, was a persecutor because of his harsh judgement but through mercy he became one searching for those who were far off, showing “great understanding and mercy to those who were as he had been.”

St. Augustine “was healed in his regret for being a latecomer” and would “make up for lost time by writing his Confessions.”

Brochero, who spent his days going from one village to another on a mule building churches and schools in the province of Cordoba, is according to Francis an example of “letting things go” and accepting that sometimes, things are left unfinished.

“In the end, his vessel was his own leprous body,” Francis said. “He wanted to die on horseback, crossing a mountain stream on the way to anoint a sick person.”

Yet of all the vessels, the pope continued, there’s not one more “simple yet perfect” than the Virgin Mary, who “gazes” especially at priests, “since through us she wants to gaze at her people.”

Francis said that Mary allows priests to “feel her maternal embrace” and that only she “can remove the myopia that fails to see the needs of others, which are the needs of the incarnate Lord, as well as the hyperopia that cannot see the details, ‘the small print’.”

He said that Mary also has the ability to “wave,” meaning to “bring good out of all the things that her people lay at her feet,” and to offer-and inspire- “attentive care” because her gaze “is one of complete attention.”

“Like a mother, she is all ears for the child who has something to tell her,” he said.

Lastly, Francis concluded before leading the priests in prayer, Mary’s gaze is “integral, all-embracing. It brings everything together: our past, our present and our future.”

In the afternoon the Argentine pontiff delivered his last meditation, “The good odor of Christ and the light of his mercy.”

Above all, this address was an invitation for priests to be merciful, saying it’s not “a way of life” but “the way of life.”

He quoted Brochero to make his point: “The priest who has scarce pity for sinners is only half a priest. These vestments I wear are not what make me a priest; if I don’t have charity in my heart, I am not even a Christian.”

Here he used the Gospel passage of the woman caught in adultery. When Jesus encounters her, he’s asked “should she be stoned or not?”

“He did not rule, he did not apply the law. He played dumb, and then turned to something else,” Francis said, adding that in doing this Jesus started a process in the heart of a woman who needed to hear, “Neither do I condemn you”.

The passage continues with Jesus telling the woman “Go and sin no more.” The pontiff said he’s saddened and annoyed when people go straight to those words.

Francis told the priests that in talking to the woman, Jesus opens several spaces: one is that of non-condemnation, “Where are those who condemned you?” The second space, that of “sin no more” has to do “with the future,” is a command to help her “make a new start and to ‘walk in love’.”

The pontiff also spoke of the confessional, which he defined as the place “where the truth makes us free.” He said that priests are called to be “instruments” so that the faithful can have a “face-to-face” encounter with God’s mercy.

“What people do afterwards is their business,” he said, before giving two pieces of advice for the confessional: A priest hearing confession should never look like a bureaucrat or a judge, he said, and he should never “be too curious.”

Finally, Francis meditated on the Works of Mercy, which, according to Catholic tradition, include seven “spiritual” and seven “corporal” works.

Francis asked the priests not to think of them individually, such as “hospitals for the sick, soup kitchens for the hungry,” but as a whole: “The object of mercy is human life itself, and everything it embraces,” he said.

As “flesh,” human life needs clothing, shelter, and burial, and as “spirit” it needs to be educated, corrected, consoled, the pope said.