RIO DE JANEIRO -- Pope Francis arrived in Brazil on Monday, returning to his native South America on his first official trip since he became pontiff in March and started shaking up the Catholic church with his more personal, humble style. The pope waved as he descended the stairs from his plane and was formally received by Brazilian President Dilma Rousseff. Thousands of young pilgrims in multicolored T-shirts had gathered hours earlier in downtown Rio, which closed off its streets in anticipation of the Argentine-born pope's arrival for World Youth Day, an annual get-together of Catholic young people. Francis has reportedly thrown local authorities for a loop by refusing to tour streets in a bulletproof version of the famous "popemobile," insisting instead on remaining exposed in an open-air car. "I want to see him and feel him close to me," said Carlos Alberto Fahd, a 23-year-old student who traveled from northern Brazil for the pope's arrival. Francis is already changing the church with his simplicity. A large group of Brazilians united with some Puerto Ricans, communicating in a combination of Portuguese and Spanish, and insisting on helping visitors find their way to Rio's main cathedral. Observers across the country will be eager to see what comes of Francis' meeting with Rousseff, scheduled for later Monday. In particular, they will want to know how a demonstration planned on Facebook will compare to the protests that spread throughout the country last month, largely over economic issues. Devout Catholics are hoping the pope's charisma will bolster the country's faithful this week. Brazil is the world's largest Catholic country, but it is less Catholic than it has ever been. According to a poll carried out recently by the local Datafolha organization, only 57% of Brazilians identify themselves as Catholics, and fewer than 16% say they attend weekly Mass. On the flight to Brazil, Francis spoke to reporters, decrying unemployment among youth and society's disregard for the elderly. Local media reports said Rousseff would propose concerted anti-poverty efforts around the world in her meeting with Francis. Young people who have gathered in the streets of Rio de Janeiro have praised Francis' desire to bring the church closer to common people and to create a "poor church for the poor." Royal baby watch: Catherine, Duchess of Cambridge, in labor