SAO PAULO, Brazil — Pope Benedict XVI is heading to the world's most populous Roman Catholic country at a time when evangelical Christians are packing cavernous churches every Sunday.

Benedict will try to halt that wave of Protestant fervor during his first trip to Brazil. Aiming to energize its more than 120 million Catholics, Benedict will canonize the country's first native saint, hold Masses that could attract millions and open a conference of Latin American bishops in the holy shrine of Aparecida.

Few believe the five-day papal visit, which begins Wednesday, will reverse the flight of Catholics who have abandoned the church to become Protestants — or who simply stopped attending Mass.

Nearly half the world's 1 billion Catholics live in Latin America, but Pentecostal churches are enjoying explosive growth, promising divine intervention to lift parishioners from lives of misery in a region where the divide between rich and poor is huge.