APARECIDA, Brazil - Pope Benedict XVI concluded his visit to the world's biggest Roman Catholic country yesterday by warning against "authoritarian forms of government" and calling on Catholics to reinvigorate the church.

Speaking in Spanish to more than 160 Latin American and Caribbean bishops, the 80-year-old pontiff denounced both Marxism and capitalism and defended the Roman Catholic Church's often-bloody campaign to Christianize indigenous people.

His hour-long speech contained the lengthiest and most pointed remarks of the pope's five-day visit, and it was meant as a guide to the bishops as they begin a 19-day conference on the church's future in the region.

At the top of their agenda will be halting the exodus of millions of Catholics from the church during the last two decades, a challenge the pope referred to while urging the bishops to fight "secularism, hedonism, indifferentism and proselytism by numerous sects." Catholic leaders often refer to Latin America's booming Pentecostal congregations as "sects."

Benedict's most political remarks appeared to be aimed at the region's new generation of leftist leaders, such as Venezuelan President Hugo Chavez and Bolivian President Evo Morales, who have been accused of ruling autocratically.

"In Latin America and the Caribbean, as well as in other regions," the pope said, "there has been notable progress towards democracy, although there are grounds for concern in the face of authoritarian forms of government and regimes wedded to certain ideologies that we thought had been superseded, and which do not respond to the Christian vision of man and society as taught by the social doctrine of the church."

Echoing the words of his predecessor, Pope John Paul II, Benedict said "the Marxist system, where it found its way into government, not only left a sad heritage of economic and ecological destruction, but also a painful destruction of the human spirit."

The pope appeared to criticize indigenous leaders such as Morales, an Aymara Indian, by denouncing the revival of native religions. Since he took office early last year, Morales has given native beliefs a higher public profile and threatened to eliminate Catholic instruction from the country's schools.

The pope also tackled some issues dear to Latin American leftists who oppose the free-market reforms of the 1990s.

While praising "the phenomenon of globalization" as a sign of people's "profound aspiration towards unity," Benedict warned that "it also undoubtedly brings with it the risk of vast monopolies and of treating profit as the supreme value."