It was in Aparecida in 2007 that Pope Frances, then Cardinal Jorges Mario Begoglio of Buenos Aires, co-wrote a document calling for Catholics in Latin America to become missionaries and fight against social ills, USA Today reported.
"The language that the bishops used in Aparecida is the language that the church is using now," said Robert Coogan, an American priest in Mexico and an observer of the Latin American church. "Instead of thinking, 'The priests have to do something,' it's for each person to think: 'I have to do something. I have to make a difference.'"
The trip to Aparecida is Francis' first event during World Youth Day, a gathering of more than 300,000 Catholics from the world over.
He arrived in Brazil Monday to a crush of well-wishers who swarmed his convoy in Rio de Janeiro and prevented him from reaching his reception ceremony on time.
Another observer told USA Today that it is hoped Francis' visit to the world's most populous Catholic country can reinvigorate a region that has seen a shrinking congregation.
"We see some of the same energy [with young Catholics] that we haven't seen since Pope John Paul II, says Andrew Chesnut, religion studies professor at Virginia Commonwealth University. "But whether it translates into numbers or real growth, especially in Latin America, where the church is most concerned, remains to be seen."
The young people Pope Francis may meet in Brazil might not necessarily represent young Catholics worldwide, however, the Los Angeles Times reported.
A Brazilian Institute of Public Opinion and Statistics survey indicated 82 percent of Brazilian Catholics ages 16-29 think they should be able to use the so-called morning after pill to prevent pregnancy, 72 percent support ending celibacy for priests, and 62 percent believe women should be allowed to become priests.
The survey also indicated 62 percent oppose criminalizing abortion and 56 percent accept same-sex marriages or civil unions.
The survey polled 4,004 people across Brazil in May and June and has a margin of 2 percentage points.
Leonardo Boff, a former priest and theologian who clashed with previous popes over his support for left-leaning theology, welcomes Francis while noting that the Brazil the pope will see during his visit isn't a place devoted to Catholic orthodoxy, the Times said.
"Brazilians are profoundly religious. They see the presence of God in everything," Boff said. "God isn't an object of faith, but of experience. But this doesn't mean they are doctrinaire in their Catholicism. The vast majority don't follow Catholic doctrine because they don't know it well. Brazilians are cultural Catholics, not orthodox Catholics."