He calls his church a field hospital for the spiritually wounded. And on Friday, Pope Francis spoke to hundreds who are still trying to heal.
Praying with families of victims of the September 11 attacks at a ground zero memorial and speaking at an interfaith service, Francis offered a message of hope at a place of horror.
"The name of so many loved ones are written around the towers' footprints. We can see them, we can touch them, and we can never forget them," Francis said.
"Here, amid pain and grief, we also have a palpable sense of the heroic goodness which people are capable of. ... Hands reached out, lives were given.
"This place of death became a place of life, too, a place of saved lives, a hymn to the triumph of life over the prophets of destruction and death, to goodness over evil, to reconciliation and unity over hatred and division," Francis said.
'This really is the beginning'
At a place that's often the site of somber memorials, the arrival of Pope Francis brought a chorus of cheers and chants.
Outside the National September 11 Memorial & Museum, about 1,000 family members of victims of the 2001 terror attack greeted the pontiff.
Standing steps away from where their relatives perished, they lined up along guard railings to catch a glimpse of Francis.
Some got the chance to talk with him one-on-one. Others watched from behind barriers, trying to catch his attention.
A man shouted: "Francisco! Our whole family's here! A blessing, please!"
It wasn't long before the crowd joined him: "Our blessing, please! Francisco! Francisco! Francisco!"
Nixia Mena-Alexis held a bouquet of yellow roses in one hand and wore a photograph of her sister pinned to her shirt.
The flowers, she said, symbolize the Catholic Church -- and hope. She said she hoped to give some to the Pope and place some beside her sister's name -- one of thousands surrounding the reflecting pools at the memorial.
Diarelia Mena worked in IT for Cantor Fitzgerald. She had just turned 30 and had a 2-year-old daughter when she was killed on September 11.
"She was full of life and her laughter was contagious," her sister said as her eyes filled with tears.
The lifelong Catholic said coming here fills her with a mix of emotions. But Mena-Alexis knew she wanted to be here when the Pope came.
"To me, he symbolizes peace, and that's part of what we're striving for after what happened here," she said. "This is sacred ground, so I wanted to be present when he came."
Jean Colaio, 50, lost her two brothers on 9/11. Both worked at Cantor Fitzgerald.
Being in the Pope's presence, she said, will help heal her family.
"We were here on that day and witnessed everything and evacuated. We had our horrible experience here," Colaio said. "And this really is the beginning. We've been working on our healing. But I think this really has propelled it.
"I feel close and connected to my brothers because he's here."
Marjorie Kane, whose father was killed on 9/11, said she felt differently after seeing the Pope than she ever had at the site.
"It's honestly the first time I can recall being on this ground and feeling this peace and calm," she said. "I'm usually full of such sorrow and such sadness coming here."
It wasn't just Catholics who said they were inspired by the Pope's message.
Dr. Gunisha Kaur, who offered a Sikh prayer onstage at the ceremony, is pregnant and asked the Pope to bless her baby.
Onstage, before the crowd, he placed his hand on her belly.
"That is the power of this pope, that he means something to all religions," her husband, Simran Jeet Singh, said after the service.
Kaur said she was moved by Francis -- and all the faiths that were part of the program.
"During prayers that were in languages that I don't know, I I found myself singing along," she said. "It really felt like we were all there praying together."
On the global stage
Before his visit to the memorial, Francis addressed a global stage at the United Nations. He presented himself as a champion of the poor and suggested solutions for leaders to adopt to combat war, environmental destruction and poverty.
Francis said the selfish pursuit of power and wealth is hurting the environment and the poor.
"A selfish and boundless thirst for power and material prosperity leads both to the misuse of available natural resources and to the exclusion of the weak and disadvantaged," Francis said.
Later Friday, Pope Francis will take a quick spin through Central Park after visiting Our Lady Queen of Angels School in East Harlem.
The stop at the school, with 295 mostly Latino and black children, is in line with Francis' mission of serving immigrants, the marginalized and the poor.
"This is his most important stop," said Monsignor Kevin Sullivan, executive director of Catholic Charities.
Francis will end his day celebrating Mass in Madison Square Garden, home to sporting events, concerts and other shows. It's the fourth-busiest music arena in the world based on ticket sales and can hold 20,000 people.
Francis' visit bumped a Billy Joel concert originally slated for Friday night to Saturday.