As of the past few decades, it is clear that Catholic clergy are witnessing a mushrooming demand for exorcisms. An astonishing number of people undergo deliverance from demonic forces every week, not only in the developing world but also in Britain and the United States.

Pope Francis, who regularly speaks about the Devil, has told priests that they “should not hesitate” to call on exorcists if they hear confessions or see behaviour indicating satanic activity. Just a few months into his pioneering pontificate, Francis himself performed an informal exorcism on a man in a wheelchair in St Peter’s Square. The youngster had been brought by a Mexican priest who presented him as demon-possessed. The Pope intently laid two hands upon the man’s head, clearly concentrating on driving out the demons.

The first Latin American Pope advocates exorcism as a potent weapon for doing battle against the Enemy and his legions. Like most of his fellow Latin Americans, Francis regards the Devil as a real figure who sows discord and destruction in the world.

Last April, the Vatican organised an exorcism workshop in Rome. More than 250 priests from 51 countries assembled to learn the latest techniques to exorcise demonic spirits. Alongside the usual spiritual paraphernalia of holy water, Bible and crucifix was a new addition: the mobile phone, in keeping with the global technological zeitgeist, for long-distance exorcisms.

Exorcism is, of course, an ancient feature of the Catholic faith. It was an essential part of early Catholicism. Deliverance from demons fell within the purview of holy individuals, both living and dead, and had no particular formalities attached.

In the Middle Ages, exorcisms altered, becoming more indirect. Frequently spiritual intermediaries such as salt, oil and water were used. Later, the holiness of saints and their shrines, deemed capable of miracles, began to take precedence over actual exorcisms. In the medieval era exorcism became a marginal practice, morphing from an ecstatic performance to a liturgical rite involving priestly authority.

During the Reformation, as the Catholic Church struggled with Protestant attacks and internal divisions, its practices came under the spotlight. Exorcism was consequently reclassified and subject to stringent methods as the Church sought to establish strict criteria of diagnosis and canonical legitimacy. Legality came to the fore. Questions arose regarding who had the authority and legitimacy to exorcise. The Catholic Church began to restrict who could perform exorcisms.

It was during the 17th century that exorcism practices were defined. In fact, the rite used today is an adaptation of the one conceived in that era. Although exorcism was declining in popularity, the figure of Satan reappeared quite dramatically as the schisms between Christian groups during the Reformation were conceptualised as an apocalyptic battle between Satanic forces and the Church of God.

With the advent of the so-called Age of Reason, defined by scientific advancements, rationalism, scepticism and a secular state, exorcism was impugned. Even within the Church some intellectuals such as Blaise Pascal, who combined a fideistic perspective on theology with openness to science, took a negative view of the practice. Exorcism manuals which had formerly circulated freely were suppressed and, despite demand from lay people, exorcisms declined.

In the 19th and 20th centuries, as modern medicine and psychology advanced, exorcism was derided. Neurological and psychological explanations, such as epilepsy and hysteria, were proffered for why people appeared to be possessed.

Exorcism returned dramatically in the 1970s. The box-office hit The Exorcist revealed the significant and still cogent belief in demonic possession and the need to deliver tormented souls from evil spirits. Priests such as Malachi Martin (who, it should be noted, was later released from aspects of his vows by the Vatican) gained notoriety due to their exorcism activities. Martin’s 1976 book Hostage to the Devil, on demonic possession, achieved considerable success. American Catholic Charismatics such as Francis MacNutt and Michael Scanlan also gained prominence, further putting exorcism in the public eye.

Yet the main impetus for the return of exorcism comes from outside the Catholic Church. The surge in the practice is strongly related to religious competition. Since the 1980s, especially in Latin America and Africa, Catholicism has faced stiff competition from Pentecostalism, the most dynamic expression of Christianity to emerge over the past century.

Pentecostal churches offer a vibrant spiritual life. They are “pneumacentric”; that is, they focus on the role of the Holy Spirit. They feature demonic deliverance as a defining element of their healing services. Pentecostalism is the most rapidly growing Christian movement in the world, rising from six per cent of the world’s Christian population in 1970 to 20 per cent in 2000, according to Pew.

Since the late 1980s competition with Pentecostalism has led to the formation of a cadre of Latin American priests affiliated to the Catholic Charismatic Renewal, which specialises in “liberation” (or exorcism) ministries. Such is current demand for release from demonic possession that some priests, such as the Brazilian Charismatic superstarFr Marcelo Rossi, even celebrate “liberation Masses” (missas de libertação) on a weekly basis. Fr Rossi has acknowledged his pastoral debt to the Brazilian Pentecostal leader Bishop Edir Macedo, whose Universal Church of the Kingdom of God brought exorcism to the fore of spirit-centred Christianity in Latin America. “It was Bishop Edir Macedo who woke us up,” Fr Rossi has said. “He got us up.”

In Cameroon, Fr Tsala, a Benedictine monk who has been a priest for more than 25 years, regularly conducts exorcisms in the capital Yaoundé. Every week he offers them to the innumerable people who come to his services, which are so popular that security personnel have to ensure that congregants do not trample one another.

“Carole” was among one of the many participants at a service last year. She had sought all the modern medical aid possible for her brain tumour, but to no avail. She turned to Fr Tsala, and following numerous prayer sessions and demonic deliverances, she claims to have seen a considerable improvement in her health.

As the Catholic Charismatic Renewal has expanded among the Latin American and African working classes, so has demand grown for physical healing and exorcism. Many impoverished urban Catholics, like their Pentecostal counterparts, seek divine help for their poverty-related afflictions. Thus, grassroots Charismatics typically implore the Holy Spirit to empower them to overcome such problems as unemployment, physical illness, domestic strife and alcoholism.

In Brazil and much of the Caribbean, possession is often attributed to the exús, or liminal trickster spirits of Candomblé, Umbanda and other African diasporic religions. In Mexico, it is increasingly the spirit of the folk saint Santa Muerte that is being expelled from possessed parishioners. In Africa, it is usually the indigenous, pre-Christian spirits that are blamed, such as Mami Wata across West Africa, or Tokoloshe in South Africa.

In the US and Britain, meanwhile, parishioners increasingly believe that demons are the cause of their various tribulations. One American we interviewed from the Deep South believed that a car he could not repair despite innumerable trips to the garage was possessed by satanic forces which he thought could only be removed by a Catholic priest.

A priest at an apostolic church in Georgia reported that the demand for exorcisms in the past two years had increased so dramatically that he could not keep up. Catholics came to him with a range of problems they attributed to demonic possession, from love and health troubles to changes in personality. Many had sought services from the state, such as psychological aid or medical care, which had failed them, before turning to the priest.

All this underlines that exorcism is on the rise and is no longer a marginal practice. With the failure of modern medicine, psychology and the mod cons of capitalism to explain difficulties, resolve troubles or offer equal opportunities to all, demons and satanic forces are often blamed for issues, whether in Africa, Latin America, Europe or the US.

Today still, when modern institutions, services and logics fail, and when injustices prevail, many believe that supernatural entities are the cause. After all, the Devil is in the detail, and for many Catholics, Satan may ultimately be to blame for the world’s ills.

Dr Kate Kingsbury is an adjunct professor at the University of Alberta. Dr Andrew Chesnut is Bishop Walter F Sullivan Chair in Catholic Studies and Professor of Religious Studies at Virginia Commonwealth University