Raúl Castro was a Jesuit schoolboy before turning to communism, and after a lengthy meeting with Pope Francis last month, he told Vatican reporters he was so impressed he was considering a return to the church. They laughed. “I’m serious,” said Castro, 84. If so, he would not be the first Cuban in recent years to find his way back to Jesus.

The island has experienced a religious revival of sorts in the past 25 years, as the demise of Soviet totalitarianism has made room for a tropical Marxism that is less than total but still highly controlling. Cuba was never a deeply pious country in the cloth of some other Latin American nations. But the Catholic church and other denominations have come a long way from the 1960s and 70s, when Fidel Castro’s revolution sent religious believers to labour camps and enshrined atheism in the constitution.

Considering a return to the church … Raúl Castro. Photograph: Desmond Boylan/AP

Today, Christmas and Good Friday are national holidays once more. Churchgoers no longer face official discrimination. For the first time in five decades, the government has given the church permission to build a cathedral. And Catholic authorities face increasing competition from fast-growing evangelical denominations, many with close ties to US churches. “There is freedom of worship now, yes,” said the Rev Roberto Betancourt, the priest at Our Lady of Regla, one of Cuba’s landmark churches. “But that’s not the same as freedom of religion.”

Indeed, no other country in the Americas is so restrictive. The Cuban government doesn’t allow the church to run its own schools, or broadcast on television or the radio. Public acts of worship or proselytising are proscribed. These limits may explain why Cuba continues to draw so much attention from the Vatican, despite a reputation for thinly attended Sunday masses. About 27% of Cubans identified as Catholic in a poll of 1,200 adults commissioned by the Univision network earlier this year. Forty-four per cent of respondents said they were “not religious”.

Still, the poll found that 70% of surveyed Cubans have a favourable opinion of the Roman Catholic church, and 80% rated Pope Francis positively, as both are viewed as powerful advocates for political and economic change. When Francis arrives here in September before his trip to the United States, it will be the third papal visit since 1998, when Pope John Paul II called on Cuba to “open to the world, and for the world to open to Cuba”. Pope Benedict XVI travelled to the island in 2012.

Francis, an Argentinian and the first pope from Latin America, has appeared even more eager to take up John Paul II’s mantle. He played a central role in the secret negotiations between US and Cuban officials that are leading to the restoration of diplomatic relations. At one point, the Vatican hosted meetings for US and Cuban negotiators, and the pope’s blessing has provided President Barack Obama with political cover as he faces opposition to the rapprochement with Castro from Cuban-American lawmakers.

By visiting Cuba and the United States, Francis will make the countries’ incipient reconciliation a central theme of his trip. “In places where there is conflict in the world, the pope makes himself present,” Betancourt said.

Francis’s schedule shows that he will spend four days on the island, celebrating masses in Havana and the large cities of Santiago and Holguin. Raúl Castro said he plans to attend all three.

Whether Francis will openly criticise Cuba’s one-party system and urge Castro to do more to open to the world – and democratic governance – remains a key question. Opponents of the communist government here and abroad would be deeply disappointed if the pope does not use his platform to push for change. He may be more likely to nudge. Francis, like Obama, is essentially following a course charted by John Paul II that seeks to gradually change Cuba by engaging the Castro government, rather than confronting it, as the church attempted to do in the 1960s and 70s.

The benefits of the engagement approach are evident today in the rehabilitation of the Catholic church as the island’s only significant independent institution. Cardinal Jaime Ortega, Cuba’s highest-ranking prelate, has negotiated directly with the government for the release of political prisoners. The church publishes magazines, hosts lecture forums open to Cuban dissidents and has organised MBA courses for aspiring entrepreneurs. Such privileges are somewhat resented among other Christian denominations on the island, which cannot match the Catholic church’s institutional profile.

Evangelical Christianity has made inroads among migrants who arrive in Havana and find community through the church

Religious leaders and communist officials seem to share a sense of alarm over what both groups perceive as a “crisis of values” among Cuban youth, even if they differ on the root causes. Ideological differences notwithstanding, both see a generation of Cuban young people eager to obtain material goods, with loose sexual mores and even looser commitments to the social objectives of Fidel Castro’s revolution.

But while Catholic leaders are trying to win them back with an institutional resurgence, evangelical Christians are going into the streets to do it. “We are living in a society that has lost its values,” said Yoel Guevara, a 32-year-old evangelical pastor. “Christ gives them back.”

Cuban authorities and the Catholic church both look warily on the rapid spread of evangelical denominations across the island, as hundreds if not thousands of tiny churches have popped up in Cubans’ living rooms. There is often no hierarchical structure for the Cuban government to relate to, and many smaller Christian groups have resisted the government’s attempt to organise them. (The island also has small Jewish and Muslim communities.)

Guevara’s group is affiliated with Victory Outreach International, a Pentecostal order founded on the streets of Los Angeles that is known for evangelising among addicts, inmates and the homeless. In Cuba, the group has no church, but Cuban authorities allow them to congregate Sunday mornings for worship along Havana’s Malecón seawall. They bring their own generator to power the microphone and the speakers, attracting hundreds.

“The presence of Christ is strong where sin is abundant,” said Daniel Delis, wearing long dreadlocks, after a small church weeknight service in a fellow member’s home. He said his faith helped him overcome an addiction to marijuana.

Like Catholic leaders, Cuba’s evangelicals oppose abortion, which is legal in Cuba, as well as the highly publicised efforts of Mariela Castro, Raúl Castro’s daughter, to win same-sex marriage rights and other protections for gay Cubans. The Pentecostal group says it goes out on weekend nights to walk among the revellers along Havana’s seawall, attempting to convert gays and occasionally facing police harassment.

The issue is a reminder that while the Cuban government holds the reins, its social policies are sometimes calibrated to balance among different groups.

Evangelical Christianity has made inroads especially in poorer eastern Cuba, and among migrants from rural Cuba who arrive in Havana and find community through the church’s open doors and animated style of worship.

The Rev Ricardo Pereira, the bishop at the Methodist church of Marianao in Havana, said his church has gone from fewer than 400 members in the late 1990s to more than 3,200 today. There are three worship services on Sundays to accommodate them. His services draw everyone from dissidents to military officials and the families of US diplomats. Like other “charismatic” forms of worship, Pereira’s sermons are rollicking, hallelujah affairs, featuring electric guitars and drumming. “The great majority of Cubans have African blood,” he said. “We show our devotion with drums and a lot of shouting.”

The Methodist church of Marianao in Havana had fewer than 400 members in the late 1990s, but has more than 3,200 today. Photograph: Sarah L Voisin/Washington Post/AP

In some ways, he and others have won followers by making Christian devotion more like Santería, a form of spirit worship that blends African deities with Catholic saints. It is perhaps more pervasive in Cuba than ever, and even as Christian leaders of nearly every denomination label it “idolatry”, they have incorporated more music and dance into their services.

“Other denominations want Cubans to stop being Cuban when they enter the church, and sit there like Europeans or Americans,” Pereira said. “We want to dance and be Cuban.”

This article appeared in Guardian Weekly, which incorporates material from the Washington Post