The ongoing Synod for the Pan-Amazon Region—to be concluded on Oct. 27 in Rome—must address the region’s challenges through a creative combination of respect for the Catholic tradition and openness to local realities. That is the assessment of the sociologist Francisco Borba Ribeiro Neto, the coordinator of the Center of Faith and Culture at the Pontifical Catholic University of São Paulo.

According to priests and women religious who have worked in the Amazon for decades, the particularities of the Catholic mission in the region—especially the lack of clergy to attend to thousands of geographically isolated communities—has led them to make hard choices. Over the years, new ways of pastoral care have had to be tested, usually derived from local habits, traditions and cultures.

“It needs to be clear that the Amazon—as well as great portions of the South American countryside—historically suffered from a very serious lack of priests. The consequence was the formation of a popular form of Christianity, in which the absence of a basic religious education prevented the people from grasping the differences between the several Christian denominations,” Mr. Borba said.

According to priests and women religious who have worked in the Amazon for decades, the particularities of the Catholic mission in the region—especially the lack of clergy to attend to thousands of geographically isolated communities—has led them to make hard choices.

This situation not only accounts for the recent progress of neo-Pentecostalism in the Amazon region but also has led to a kind of Catholicism mainly based on the popular devotion of saints—and not in the sacraments.

A historical tradition of the church in the Amazon has been the desobriga (from the Portuguese verb desobrigar, meaning “to disoblige” or “to release”), in which a bishop or priest visits several communities that have gone up to 15 years without the presence of a member of the clergy and administer all the sacraments at once. Nowadays, visits are more frequent, but many faraway communities still receive a priest no more than once a year.

“The other day, I traveled to celebrate a Mass at a community that hadn’t seen a priest for two years,” the Rev. João Carlos Andrade Silveira of the city of Anapu, in the Brazilian state of Pará, told America. It was one of 70 communities in Anapu, a city with a total area of 11,900 square kilometers—bigger than a country like Kosovo, for instance.

“In the meantime, they lead their lives, praying the rosary and doing weekly celebrations of the Word—which they usually call ‘service’ due to the influence of the evangelicals,” said Father Silveira. In many communities, Eucharistic ministers and catechists play the role of religious leaders, doing baptisms and witnessing matrimonies.

Women religious also play a central role in Amazonian communities. They certainly outnumber the priests and seem to reach more places. The way they are seen by the people—sometimes akin to priests—is a natural result of their work.

When Sister Ivone Oliveira first arrived in the Amazon, 20 years ago, she spent six years in the northern Brazilian state of Rondônia, in a parish that did not have a priest. She and her colleagues had to ensure that all the 24 communities of the region were visited, doing baptisms and matrimonies and also offering classes of religious and social education. Over time, they also formed lay community leaders.

Women religious also play a central role in Amazonian communities. They certainly outnumber the priests and seem to reach more places. The way they are seen by the people—sometimes akin to priests—is a natural result of their work.

“Many people would come to us and say they needed to confess their sins. We always made clear we couldn’t forgive them in the name of the church. But we obviously listened to them, gave them a blessing and a hug,” she told America. But if the nuns understood that a priest was important for a given occasion, they would make a huge effort to bring one to the city.

After a few years, when finally a priest settled in the region, people still asked to “confess” first with a nun. “They trusted us very much and used to ask us if they could tell this or that to the priest,” said Sister Oliveira. “Many of them were traumatized with ancient priests that were too moralistic and yelled at them depending on the sin. The priest gave us full support on this task.”

Luigi Ceppi, an Italian-born priest who has been living in the Brazilian state of Acre for decades, remembers some hard decisions he has had to make. “After one day of ‘desobriga’ in a very faraway community—it took us 15 days traveling on a boat to get there—I was approached by a family who wanted to baptize their kids. They heard we were there and came to us,” he told America.

Father Ceppi asked them about their knowledge of Jesus Christ, Catholic prayers and so on. “They told me they didn’t know much about any of that. I was in doubt if I should baptize them under those circumstances. But then they told me they had traveled for 18 days to get to me, through the rivers and the forest.”

So he decided to baptize them. “What was more important: the effort they made or the sacrament’s doctrine, the need of a preparatory course and so on? They were very happy to know they were the children of God.”

Sister Miriam Spezia, who lives in Acre near the borders of Peru and Bolivia, explained that for many people in the region, baptism is seen as an obligation, but they do not view the other sacraments in the same way. “Their experience of religion in our region is largely based on the Gospel, the collective reflection on it and its concrete application in their daily lives,” she said. She has been working in the region for 30 years, but she said that only in the last five years has the parish regularly seen a priest.

The vast distances and lack of infrastructure are constant obstacles for Catholic missionaries in the Amazon. “We normally schedule a week or two to visit the riverside communities, but it’s too expensive for us. What keeps their faith while nobody visits them is their devotion to saints,” explained Sister Vilma Padilha from the city of Borba, in the Brazilian state of Amazonas. “In some communities, there are men who certainly could assume some kind of priesthood, in case the synod approves the possibility of the viri probati [certain married priests]. This would be a great help.”

The lengthy and frequent travel required under the current model of the Amazonian church is also costly for communities that are often struggling financially. “This year the communities in our region are very happy because despite their poverty they were able to contribute with 22,000 reais,” about $5,350, “to the parish. But our annual expenditure with transportation equals 20,000,” about $4,870, said Sister Oliveira.

Eduardo Campos Lima is a freelance journalist who contributes from São Paulo, Brazil.