An estimated 150,000 pilgrims greeted the pope as he arrived outside the basilica at Aparecida, south-west of Sao Paulo, the BBC reports.
The Pope was then due to open a major conference of Latin American bishops, which will discuss ways to extend the Church's reach in Latin America.
Aparecida is home to Our Lady of Aparecida - a statue of a black Virgin Mary and the patron saint of Brazil.
In his final engagement, the pope speaking outside the Basilica of Our Lady, one of the world's largest cathedrals, said the Church would grow by attracting new members, not by proselytising to reluctant audiences.
"This is the faith that has made [Latin] America the 'continent of hope'", he said.
"Not a political ideology, not a social movement, not an economic system."
Despite the Pope's optimistic message, reports said the size of the crowds was smaller than the 500,000 that organisers had expected.
The issue of attracting or keeping members will be high on the agenda at the two-week bishops' conference, which will bring together 169 bishops from across Latin America.
The rise of evangelical churches and the Vatican's traditional conservative stance on social issues are among the key obstacles to reviving the attraction of the Church in Latin America, correspondents say.
"We need to find ways to evangelise more effectively so that people become true Catholics," Bishop Jose Antonio Tosi Marques from the Brazilian city of Fortaleza told reporters.
Bishop Erwin Krautler from the Amazon state of Para said the Church must do more to help the poor. "We often forget that the poor and landless have a right to a dignified life."
Krautler was a friend of Dorothy Stang, a US nun murdered in Para in 2005 by ranchers opposed to her work with landless peasants in the Amazon.
He defended Liberation Theology, a movement in which priests and lay people allied themselves with the poor against military dictatorships in the 1970s and 1980s. As Cardinal Joseph Ratzinger, the current pope led a Vatican crackdown on the movement.
"The right to liberation is in the Bible. Liberation Theology is a purely Latin American aspect of the church that deserves respect," Krautler said.
Earlier, several hundred thousand people attended an open-air mass in Sao Paulo on Friday to see the Pope canonise Brazil's first saint, Franciscan monk Friar Galvao.
And in a visit to a drug and substance abuse centre, the Fazenda da Esperanca (Hope Farm), in Guaratingueta, about 30 km from Aparecida, Pope Benedict urged young people who kicked the habit to carry the torch of hope that faith offers to people of their age and to society.
God shall call those who deal in drugs to account because "human dignity cannot be trampled upon in this way", the pope said according to an AsiaNews report.
"The harm done will receive the same reproach that Jesus reserved for those who gave scandal to the 'little ones', God's favourites", the pope said.
"I urge drug-dealers to reflect on the grave harm they are inflicting on countless young people and adults from every walk of life. God will call you to account for your deeds," he added.
"We see the high death rate among young people, the threat of violence, the deplorable proliferation of drugs which strike at the deepest roots of youth today. For these reasons, we hear talk of a 'lost youth,'" the pope also said in his earlier address to young people in Sao Paulo.
"My appeal to you today, young people present at this gathering, is this: Do not waste your youth. Do not seek to escape from it. Live it intensely. Consecrate it to the high ideals of faith and human solidarity," he said.
Pope visits Brazilian drug clinic (BBC, 13/5/07)
God will call drug dealers to account, says Pope (AsiaNews, 13/5/07)
Pope tells enthusiastic Brazilian youths to live fully, responsibly (Catholic Online, 12/5/07)
Pope holds final Brazil trip Mass (BBC News, 13/5/07)
Pope decries rich-poor gap in Latin America (Swissinfo, 13/5/07)
Pope: Church has "irresistible missionary power", no proselytism (AsiaNews, 13/5/07)
LINKS (not necessarily endorsed by Church Resources)
Catholic Church in Brazil (Catholic â€“Hierarchy)
Benedict backs excommunication for pro-abortion pollies (CathNews, 10/5/07)
14 May 2007