Cubans in Havana walk under a poster of Pope Francis, which reads "Welcome to Cuba," on Sept. 14. (Enrique de la Osa/Reuters).

HAVANA -- On paper, at least, Catholicism is Cuba's most widely held faith.

But long-suffering Cubans who need a little luck, or love, or a new refrigerator tend to direct their prayers to Catholic saints they typically summon by their Santeria names: Oshun, Changó, Elegua.

When Pope Francis arrives here Sept. 19 for his first visit to Cuba, he will find a country with a somewhat shallow commitment to Sunday Mass but deep currents of spirituality, and an abiding devotion to the Afro-Cuban orishas who blend Catholic icons with ancestral African deities.

This conflation -- "syncretism" in academic parlance -- has long been a challenge for church authorities who consider it idolatry or theological confusion. But Pope Francis, who considers his role as an evangelist to be paramount, may also see this basic religiosity as an opportunity.

"The faith is not something that can be imposed; it must be proposed," said the Rev. Roberto Betancourt, the priest at Our Lady of Regla, a church beside the Bay of Havana.

Santeria practitioners identify Betancourt's church with the ocean goddess Yemayá, the protector of fishermen, expectant mothers and the rafters who risk their lives crossing the Florida Straits. The pope can respect this type of syncretism as an expression of Cuban culture, Betancourt said, without accepting it as Catholicism.

"The pope is a man of this century, and in this century, you have to approach the world with understanding," said Betancourt. "This is not a time for condemnation, but for evangelization."

Only 27 percent of Cubans identified as Catholic in a recent survey, the lowest in Latin America. Yet Cuba is a country that remains hungry to connect to something greater, more mystical perhaps, and certainly less ideological than Cuban politics.

In other words, it could be just Pope Francis's kind of place.

Francis is the first Latin American pope, of course, and that has a significance beyond geography. He is an ardent defender of the passionate, folkloric ways that his Catholic faith is practiced in Latin America, especially among the poor.

As my colleague Anthony Faiola wrote recently from Italy, Francis has puzzled some Vatican observers but electrified many faithful with his embrace of "popular devotions" -- the iconography, religious relics and miracle-work that are so important to the Catholicism of Mexicans, Brazilians and so many other Latin Americans.

Countless Cubans who may not be outwardly religious or churchgoing nonetheless maintain colorful shrines in their homes with votive candles, flowers, fruit or pastries. They are portals to the spirit world of Santeria, whose orisha deities came to the island centuries ago with the West African slaves. They continued to secretly worship their ancestral spirits by merging them with Catholic saints.

Cuba's patron saint, the Virgin of Charity of El Cobre, is also Oshun, the goddess of love and fertility. Saint Jerome and Saint Barbara are Changó, the god of fire, war, music and male virility.

As a Latin American prelate, Francis has observed first-hand the church's ongoing loss of followers to Pentecostalism and other "charismatic" evangelical movements, whose worship services integrate electric guitars, drum kits and dancing to get the faithful out of their seats (and out of their bodies).

The same trend operates in Cuba. Though the church has made a significant institutional recovery since John Paul II's historic 1998 visit, Catholicism here has been losing ground to the rollicking evangelical movements sweeping the island.

"In the context of precipitous Catholic decline in Latin America, the Cuban case is of the utmost urgency" for the church, according to Andrew Chesnut, a religious studies scholar at Virginia Commonwealth University.

"Enthusiasm for both Santeria and Pentecostalism, the leading type of Protestantism on the island and all of Latin America, is greater than for Catholicism, which historically has never been very dynamic throughout the Caribbean," wrote Chesnut in an essay for The Dialogue.

"Cognizant of this, the charismatic pope, who is immensely popular among Cubans, seeks to generate the type of excitement felt during his Brazilian and South American trips, especially among Cuban young people," he said.

"No doubt, large crowds will turn out across the island to see the first Latin America pope," he wrote, "but will the excitement of the moment translate into more parishioners in the pews?"