Pope Francis, the Argentinian pontiff who has by turns electrified, confounded and provoked Americans with his fresh take on an ancient faith, comes to the United States for the first time this week. He will speak with national leaders in Congress, world leaders at the United Nations, and immigrants and prisoners in Harlem, New York; Philadelphia; and Washington.

After his arrival from Cuba on Tuesday, Francis will meet President Barack Obama on Wednesday, and on Thursday, he will become the first pope to address a joint session of Congress.

Over six days, he will address the U.N. General Assembly in New York and visit immigrant seamstresses in Harlem. He will pray with leaders of other faiths at ground zero in New York, and in Washington he will canonize an 18th-century Spanish missionary to California.

A crowd of a million or more is expected at a huge outdoor Mass in Philadelphia on Saturday.

For them, as well as those following on C-SPAN and EWTN, next week’s visit will be the first chance to get an extended look at Francis, 21/2 years into his papacy.

The first Latin American to head the 1.2 billion-member church, Francis has jolted both global and American Catholicism with his passion for the poor, his critiques of the excesses of capitalism, his alarm at environmental degradation — and within the church, an insistence that it get out of its comfort zone and “go to the margins” of society with a message of mercy.

Then there is the matter of his personal style.

Unlike his predecessors, St. John Paul II and Benedict XVI, Francis, 78, is not primarily a scholarly philosopher-theologian. He is a Jesuit pastor, formed by his long contact with the poor in the barrios of Buenos Aires.

In Rome, he has pioneered a new way to be pope: He lives in a modest apartment, accedes to tourists’ request for selfies and sometimes scolds Vatican bureaucracy for its elitist insularity.

He telephones people who have written him about their problems. He has provided the homeless with haircuts and showers at the Vatican and washed the feet of prisoners, including a Muslim woman, during a Holy Week ceremony.

He has asked to visit more prisoners during his day in Philadelphia.

“Overall, the message has not been radically different,” said Allen Stevens, a deacon at St. Peter Claver Church in New Orleans, who will go to Philadelphia to see the pope. “But what’s different is that he’s out there among the people. Seeing him in a prison cell, kissing a prisoner’s feet, is what we see in the Gospel. But he’s not just talking about it; he’s exemplifying what we as Christians need to do. And not just Christians but people of all faiths.”

Afflicting the comfortable

According to writer Paul Elie in a Vanity Fair profile, Francis reportedly shook the hand of a newly wed husband at an audience in Rome recently and added some homely advice: “Look, if some dishes fly in your house, don’t worry about it.”

David Dawson, the head of the Archdiocese of New Orleans’ Family Life Apostolate, said that while Francis’ predecessors “dug deep” to articulate a sophisticated modern theology of the family, “Francis takes it to the next level, making family life concrete in actual lives of people.”

But if at the personal level Francis has comforted the afflicted, he has also afflicted the comfortable.

In sharper tones than any pontiff in memory, he has demanded that the world’s richest countries and corporations treat the poor as Jesus would.

In “Laudato Si,” his one major teaching document, and in countless speeches and appearances, Francis has talked about social and economic justice, the plight of immigrants and care for the environment as a means of caring for the poor.

“He’s able to preach and teach an old message with new spirit,” said New Orleans Archbishop Gregory Aymond, who will travel to Philadelphia to be with Francis. “I think he takes some parts of our faith that have not had as much attention, and he’s raising them, not just to our attention, but saying, ‘This is essential.’

“He’s saying, ‘This is who Jesus is,’ and we’re required to follow.”

Francis is expected to speak directly to those themes before Congress and at the U.N., although he may temper the language he used at a conference of grass-roots organizers in Bolivia last summer.

There, he insisted that all people have a right to the “three L’s”: land, lodging and labor. He took governments and corporations to task for damaging the environment. He told his audience that “cowardice in defending (the environment) is a grave sin.”

Quoting Basil of Caesarea, a fourth- century theologian, he called the pursuit of profit over the common good “the dung of the devil.”

“Working for a just distribution of the fruits of the earth and human labor is not mere philanthropy,” said Francis. “It is a moral obligation. For Christians, the responsibility is even greater: It is a commandment.”

‘Going the extra mile’

Stevens, from St. Peter Claver, is also director of the Micah Project, which joined a national coalition of churches that recently went to the Vatican asking for an endorsement of its program, which includes an end to mass incarceration policies, an expansion of Medicare and ballot efforts to increase the minimum wage.

He said Francis sent his encouragement.

“This is nothing new,” he said of Francis’ agenda. “We’ve talked about this for years, but he’s going the extra mile. That’s the difference.

“We need to give up some of the luxuries that we have, especially if, in getting them, we are sacrificing our brothers and sisters for profit. And we are.”

But in the United States, many critics used to separating politics from religion hear that as a clarion call from the radical left — an embrace of raw socialism.

In “Laudato Si,” his 2015 encyclical, Francis, a former chemist, described climate change as a reality beyond dispute, giving American conservatives another reason to dislike him.

His decision to celebrate his Washington Mass in Spanish has agitated many still more, although the man he will canonize, the friar Junipero Serra, was a Spanish missionary, and Hispanics are the fastest-growing arm of American Catholicism.

Even on purely church matters, Francis has unsettled conservative American Catholics.

His rejection of pomp seems to some to belittle what they see as the visible, historic majesty of global Catholicism. And although he is as opposed to abortion as every other Catholic prelate, his 2013 admonition to Catholics not to behave as though abortion were the only matter that counts carried a whiff of retreat for some staunch anti-abortion conservatives.

Comparisons to Obama

On conservative radio and television and in the conservative blogosphere, both religious and secular, ominous comparisons are drawn between Francis and Obama.

A Gallup Poll taken after the climate change encyclical found that Americans who described themselves as conservative had turned sharply away from Francis, with his approval rating dropping from 72 percent to 45 percent.

Still, a cluster of recent polls, including Gallup, measure the pope’s popularity at between 60 to 70 percent of all Americans, including those religiously unaffiliated.

Admirers of Francis say he is certainly aware of the currents of American politics. They hope he will address himself particularly to immigrants’ plight in a way that contrasts with Republican presidential candidate Donald Trump’s plan to build a wall along the southern U.S. border, make Mexico pay for it and deport millions of undocumented people in the U.S.

In his addresses to Congress and the U.N., Francis likely will stay close to his carefully prepared texts. But in other settings, he has demonstrated a willing confidence to go off script, often shrewdly, winning points as an especially adept communicator.

“Sometimes it’s exactly when he goes off-script that he says what he wants to say,” Aymond said. “He’s not going to be confined by other people’s expectations. He feels called to preach the Gospel and to encourage others to do so as well.”