RIO DE JANEIRO — The white sands of Copacabana beach typically draw millions of sun-worshipers, New Year’s Eve revelers, and fans for free concerts by the likes of Stevie Wonder and the Rolling Stones. In the coming week, a different sort of star promises to stir up just as much passion among devotees.
Pope Francis, the 76-year-old Argentine who became the church’s first pontiff from the Americas in March, will turn the crescent-shaped shoreline into a giant stage for his first international trip as pope, returning to the embrace of Latin America to preside over the Roman Catholic Church’s World Youth Day festival.
The pontiff is coming to the heart of a city known for pricey real estate and sexy samba with a message of humility, simplicity, and support for the poor — priorities that he has set out already in his four months as pope.
The Catholic Church in Brazil is one he knows well, aware that it is losing legions of adherents to Pentecostal churches and secularism.
But Catholic youth festivals are meant to reinvigorate the faithful, and Francis, a soccer-loving native son, is expected to rally young people with his humble and unconventional ways.
More than a million young Catholics are expected to flock to Rio to celebrate their new pope. The city overseen by the giant Christ the Redeemer statue has mobilized thousands of soldiers and police to make sure the visit goes smoothly, even as violent antigovernment protests continue to erupt a month after Brazil saw mass demonstrations nationwide.
Some residents have already prepared a uniquely Rio de Janeiro welcome for Francis: They’ve built from sand life-sized images of the pope on Copacabana, in place of the usual sculptures of bikini-clad beauties.
Rafaela Bastos, a pilgrim walking along the beach a few days before the pontiff’s arrival, said the ‘‘Francis effect’’ was already evident. As she spoke, an army of construction workers toiled at a furious clip on the beach to finish the enormous, white altar where Pope Francis will celebrate a Mass.
‘‘Francis has captivated me; he’s absolutely won me over,’’ said the 23-year-old from Brazil’s Minas Gerais state. ‘‘He’s brought the church close to the people and especially to young Catholics. He’s creative, he’s modern, he’s not changing doctrine, but he seems far more flexible and open to discussion.’’
That Francis is from Latin America ‘‘just makes him even better: He understands our culture and that brings him closer to us and allows us to understand him,’’ Bastos said.
Despite such optimism, these are worrying times for the church, and Brazil’s case is emblematic.
The vast nation was 89 percent Catholic when Pope John Paul II became the first pontiff to visit in 1980. According to the national census, that figure had dropped to 65 percent by 2010.
Such declines are happening all over Latin America, which is one of the church’s remaining strongholds amid growing secularism in Europe and the United States. Sex abuse and corruption scandals have further eroded trust in the church.
Francis’s response to the challenges has been to help find ‘‘an entirely new way to interact with the world’’ by the manner in which he communicates, said Sao Paulo Cardinal Odilo Scherer, one of two Latin Americans named to the Pontifical Council for Promoting New Evangelization created in 2010.
‘‘The church, Christianity, the Catholic faith cannot be apart from the world,’’ Scherer said. ‘‘It must be a part of the world, inside of it, and it must interact with modern society if it hopes to have repercussions and influence.’’
After meeting with President Dilma Rousseff shortly after his arrival Monday, Francis will take a day off on Tuesday.
On Wednesday he will begin his public activities in the rolling hills of rural Sao Paulo state, visiting a huge shrine built around a small clay statue of the Virgin Mary that is a figure of worship for millions of Brazilians.
In Rio, he will walk the Stations of the Cross surrounded by more than a million young devotees on Copacabana beach as part of World Youth Day festivities.