RIO DE JANEIRO » Pope Francis celebrated the last Mass of his trip to Brazil on Sunday before more than 1 million people gathered on the beach in this city, the national flags of Catholics from around the world hoisted in the air as a chorus of Brazilian priests belted out songs before the multitude. It was a vibrant display of the Vatican’s ambition of halting the losses of worshippers to evangelical churches and the rising appeal of secularism.

By various measures, Francis’s first international trip since he was named pope this year was a success. The 76-year-old Argentine, a Jesuit who is the first pope from the Americas, was greeted like a rock star by attendees to a conference of Catholic youths. He urged people to combat corruption, a top grievance in the protests shaking Brazil, and called on bishops to focus on the pragmatic needs of congregants, shifting emphasis from the abuse scandals that have plagued the Vatican for years.

"If this trip is any indication, he’s off to a strong start at revitalizing the church," said Andrew Chesnut, an expert on Latin American religions at Virginia Commonwealth University who came here to see the pope’s visit up close. "He’s been very astute on focusing on the everyday afflictions of the poor, taking a page from the evangelicals themselves."

Before scolding Brazilian clergy at one point during the weeklong visit for losing touch with their own worshippers, by appearing "too distant from their needs," Francis offered the example of visiting a medical center where drug addicts receive treatment. Still, he hewed to the Roman Catholic Church’s prevailing view on drugs, criticizing supporters of decriminalizing drug use, showing how a pope can seem at the same time to be caring and resistant to a profound shift underway in parts of the world.

"Francis is more simpatico than John Paul II, certainly more likable than Benedict, but transforming the church requires more than public relations gestures, appealing as they might be," said Peter McDonough, a scholar of religion who has written widely on the Jesuits, comparing Francis with his predecessors. "It’s doubtful, aside from a positive bump in applications to the priesthood and perhaps a groundswell in confessions, that Pope Francis’ visit to Brazil will stem the loss of congregants to evangelical and other denominations or reverse the tide of secularization."

Still, if there is any place to forge ahead with strategies aimed at fortifying the Roman Catholic Church, it is Latin America. Just three countries in the region – Brazil, Mexico and Colombia – account for about a quarter of all Catholics in the world, according to a study of the global Catholic population by the Pew Forum on Religion and Public Life. Brazil has more Catholics, an estimated 123 million, than any other country.

Yet Brazil also showcases the threats to Catholicism. Just 65 percent of Brazilians identify as Catholics, compared with 85 percent of Mexicans. Almost 25 percent of Brazilians are now evangelical, up from single-digit levels in the 1970s, and a growing number of people reject religious doctrine completely, opting for a thoroughly secular lifestyle.

Illustrating Brazil’s diversity of beliefs, various protests coalesced around the pope’s visit. One of them, a Marcha das Vadias, or SlutWalk, involved scantily clad women questioning the Catholic Church’s opposition to legalized abortion, women as priests and same-sex marriage. At one point, a man reportedly spit in the face of one of the protesters, only to have several women in the protest show him their breasts and shake their behinds at him in defiance.

But while a Carnivalesque atmosphere prevailed in some Rio neighborhoods, a more relaxed vibe was evident in many parts of the city during the pope’s visit. Pilgrims from around the world roamed through the streets. Some strummed guitars, singing religious hymns from their homelands. Thousands camped on the beach, shrugging at the blunders by local organizers like an accidental shutdown one day of the subway system.

"I will never forget this moment in all of my life," Wael Sami, 22, an Iraqi Catholic who traveled here from Baghdad, said Sunday. "I have been to many countries, but I think this is the coolest," said Sami, a student of computer programming. "When they see our flag and know there are Christian people in Iraq, they are so excited."

While shifting attention to Latin America and other parts of the developing world, Francis notably welcomed the participation during Mass of the Charismatic Catholic Renovation, a movement of singing priests, some of them heartthrobs with hit CDs, seeking to appeal to congregants with upbeat, lively strategies similar to those employed by fast-growing evangelical churches.

"I think this pope is breaking protocol," said Saulo Palacio, 35, a computer technician who attended a religious service Sunday at his evangelical church, Nova Vida, or New Life. "We don’t agree on everything, but I recognize he’s different, maybe since he’s South American," he said. "He could change things in the Catholic Church, but I’m not switching back to Catholic rites, not when my church is a happier place, with more emotion."

Getting some evangelicals to even consider a return to Catholicism may be the start of a shift in the church’s fortunes in Latin America. But some scholars warn that the Vatican remains far from undergoing a broader transformation, with Francis, who returned to the Vatican on Sunday night, opposed to allowing women a more prominent role in carrying out religious services or allowing priests to marry.

"The gestures have changed, but the dogma has not," said Fortunato Mallimaci, a sociologist at the University of Buenos Aires who specializes in the relationship between culture and religion, pointing to the example of the pope’s stance against legalizing drugs. "On social issues, Francis will be a continuation of his predecessors."

Still, it was undeniable that Francis’ easygoing and ascetic style aroused optimism among many here that the Catholic Church could be on the cusp of a long-awaited revival. Leonardo Boff, a prominent liberation theologian who was reprimanded in the 1980s by Cardinal Joseph Ratzinger, the future Benedict XVI , said Francis was repositioning the Catholic Church "from a fortress to an open house."

"We’re exiting two papacies characterized by the return to great discipline and the control of doctrines," Boff, 74, a former Franciscan priest, wrote during the pope’s visit. "With Pope Francis, coming from outside old European Christianity, he brings hope and enjoyment of life."

© 2013 The New York Times Company