PHILADELPHIA -- Pope Francis is back at the Vatican in Rome after a busy 10-day trip to Cuba and the United States.
He left Philadelphia on Sunday night after participating in the World Meeting of Families. The 78-year-old pontiff spent six days in the U.S. where he also addressed Congress and the United Nations.
The pope defended his words of consolation to U.S. bishops over the priest sex abuse scandal but says - for the first time - that those who covered up for abusers are guilty of wrongdoing.
In a wide-ranging press conference en route to Rome from his first-ever visit to the United States, Francis also declared conscience objection a "human right," explained his love affair with American nuns and discussed his own star-power, which was fully on display during his six-day, three-city tour.
He also invented a new Italian word to describe the exuberant reception he received in New York City: "stralimitata" - roughly, "beyond all limits."
Pope Francis urged hundreds of thousands of the faithful gathered Sunday for the biggest event of his U.S. visit to be open to "miracles of love," closing out his six-day tour with a message of hope for families, consolation for victims of child sexual abuse and a warning to America's bishops.
Organizers had predicted a crowd of 1 million for Francis' open-air Mass, and the Benjamin Franklin Parkway overflowed with the jubilant. They endured hours-long lines and airport-style security checks to see history's first pope from the Americas in the birthplace of the United States.
The Mass - the final event on Francis' itinerary before the 78-year-old pontiff headed on a plane back to Rome - was a brilliant tableau of gold, green and white in the slanted evening sunlight of a mild early-autumn day.
Riding through the streets in his open-sided popemobile, the pontiff waved to cheering, screaming, singing, flag-waving crowds as he made his way to the altar at the steps of the columned Philadelphia Museum of Art.
With a towering golden crucifix behind him, Francis told his listeners that their presence itself was "a kind of miracle in today's world," an affirmation of the family and the power of love.
"Would that all of us could be open to miracles of love for the sake of all the families of the world," he said to the hushed crowd spread out along the tree-lined boulevard before him.
Crowds a mile away fell silent during the Communion part of the Mass. Some people knelt on the paving stones at City Hall, a few blocks from the altar.
June Bounds, 56, of Rochester, New York, watched the Mass with fellow parishioners on a large screen set up at City Hall, closing her eyes and blinking back tears.
"It's very overwhelming," she said. "You feel like you're one body with everyone here, whether you're here, whether you're back home, whether you're anywhere in the world."
Of the pope, she said: "He's brought so much joy and holy spirit into the United States. It doesn't matter if you're a Catholic; he's just trying to unite everybody for a better world."
Earlier in the day, Francis had a different message for families scarred by the sins of the church itself.
The pope met with five victims of child sexual abuse and told them he was "deeply sorry" for the times they came forward to tell their stories and weren't believed. He assured them that he believes them and that bishops who covered up for abusers will be made to answer for what they did.
"I pledge to you that we will follow the path of truth wherever it may lead," Francis said in Spanish. "Clergy and bishops will be held accountable when they abuse or fail to protect children."
A few minutes later, he went into a meeting of bishops from the U.S. and around the world who were in town for a Catholic festival on the family and told them the same thing.
"God weeps" over what was done to the youngsters, he lamented.
The pope has agreed to create a new Vatican tribunal to prosecute bishops who failed to protect their flock, and he has accepted the resignations of three U.S. bishops accused of mishandling abuse cases.
During his first meeting with victims, held at the Vatican in July 2014, Francis similarly vowed to hold bishops accountable, but Sunday marked the first time that he had warned the bishops themselves, face-to-face, and in public.
In an apparent effort to reshape the discussion, though, the Vatican said not all the victims had been abused by clergy; some were violated by relatives or educators. The choice of victims underscored the Vatican's argument that child molestation is not unique to the church.
Victim support groups were unimpressed by the meeting, which took place at a seminary on the edge of Philadelphia and lasted more than a half-hour.
The main victims' support group, SNAP, dismissed it as an exercise in public relations.
"Is a child anywhere on Earth safer now that a pope, for maybe the seventh or eighth time or ninth time, has briefly chatted with abuse victims? No," said SNAP's David Clohessy.
The Rev. Tom Doyle, a former church lawyer who is now an advocate for victims, said that including victims of non-clergymen "seriously minimizes" the problem in the church.
As the Mass drew to a close, church officials said the next World Meeting of Families - the Vatican-sponsored festival that brought the pope to Philadelphia - will be held in Dublin, Ireland, in 2018.
Ireland is ground zero for the church's sexual abuse crisis outside of the U.S. The overwhelmingly Catholic country also recently legalized gay marriage.
Francis' journey took him first to Cuba, then to Washington and New York. Along the way, he drew large and adoring crowds, met with President Barack Obama, visited ground zero and a school in East Harlem, and addressed Congress and the United Nations, calling for urgent action on climate change and poverty.
He also issued pointed messages for a new direction of the U.S. church, twice praising the service of America's nuns, who had been subject to a recently ended Vatican crackdown. He also urged America's bishops to focus more on helping their flock through life's ups and downs rather than spending all their energy on culture wars.
Also Sunday, Francis visited a Philadelphia jail to give hope of redemption to about 100 inmates, included suspected killers, rapists and mobsters. He greeted the men one by one, telling them to use their time behind bars to get their lives back on track.
"May you make possible new opportunities, new journeys, new paths," he said, standing before a wooden chair the men had made for him for the occasion.
The blue-uniformed inmates, some of them heavily tattooed, seemed moved. They clasped Francis' hands, and two gave him a hug.
During the meeting with the bishops, Francis referred to gay marriage for the first time in his U.S. trip, lamenting the new reality in which Christians must live. But he warned that a church that does nothing but explain its doctrine is "dangerously unbalanced."
The U.S. bishops have spent considerable time and resources battling gay marriage, calling its legalization by the U.S. Supreme Court three months ago "a tragic error" and "profoundly immoral and unjust."
Pope Francis back in Rome after wrapping up US visit with huge open-air Mass
POPE US VISIT