Global migration has brought radically different religious cultures into close contact with one another, and the consequences can be painful. Recently the respected British think tank Theos issued a judicious report by Ben Ryan on Christianity and mental health, which among other things discussed the possible medical interpretations of reported episodes of demon possession and exorcism. The report warned properly of the danger of “Christian over-spiritualizing”—a “tendency to ascribe anything and everything to spiritual causes when other medical ones may exist.”

For all its cautious words, Ryan’s report was inevitably seized on by the media for the section that reported an “astonishing increase in demand” for exorcisms. These “are now a booming industry” in the United Kingdom, it said, partly though not entirely because of “immigrant communities and Pente­costal churches.” Distorted media ac­counts told of mass “spiritual abuse” by churches that exploited and harmed the mentally ill and vulnerable.

Exorcism is a crucial matter for many of Britain’s immigrant churches, especially those from Africa, where belief in possession and witchcraft is very widespread. (Britain today has around 1.5 million African-born residents.) Such churches view apparent possession cases in terms of demonic activity rather than as a mental health issue treatable by secular means.

Any dispute over the propriety of exorcism is particularly sensitive in the British context, because it recalls a dreadful religious and racial confrontation at the start of this century. In 2001, a sensational child murder case indicated the practice of witchcraft on British soil involving ritualistic killing and a trade in human body parts.

Obviously, such extreme criminal behavior demanded a strong and effective official response. But the media soon attributed such horrors to Pentecostal and charismatic churches themselves. In the sensational coverage that followed, the press launched shrieking exposés of immigrant churches that believed in spiritual warfare or practiced exorcisms. These came to be known as Witch Churches.

A potent racial theme pervaded this coverage, with a classic Heart of Dark­ness scenario portraying African primitivism and violence. Media ac­counts segued from reporting on exorcisms undertaken to fight diabolic forces to depicting the rituals themselves as a form of primitive jungle savagery dressed in Christian guise. Rituals designed to combat witchcraft were presented as a singularly dangerous manifestation of witchcraft and ritualistic child abuse. The regular conduct of immigrant churches involving exorcism and healing—without any abusive or violent element—was seen as deeply problematic and demanding police intervention.

The government responded by en­forcing far stricter rules for African clergy and ministers seeking to enter the United Kingdom, a draconian sanction introduced well before any like restrictions were imposed on extremist Muslims who flagrantly preached hatred and violence. In retrospect, the Witch Church affair was a grim example of religious intolerance— and in this instance, one directed against Christians.

We must hope that such hysteria will never be repeated. But the whole exorcism issue does raise potent questions about the role of spiritual warfare ideas within Christianity, and in the mainstream, not just on the fringes. Just what do we do about exorcism?

As the Theos report noted, exorcisms figure in scripture. The Gospel writers clearly believed that Jesus was confronting literal demonic powers and that his healings went far beyond mere psychosomatic intervention. The real and objective nature of spiritual evil emerges, for instance, in the sequence of stories like Luke’s chapter eight, which is very popular in African churches. Once the Gerasene demoniac has been exorcised, the evil spirits possessing him have to go somewhere.

Nor can such beliefs be confined to the earliest Christian ages. During the British media witch hunts of the last decade, one newspaper quoted an expert as declaring that “there are clearly exorcisms taking place in this country,” with several major investigations then in progress. Such a tiny figure might be justified if we are restricting ourselves to sensational horror stories (think of Linda Blair’s rotating head), but in terms of exorcisms generally, it is a ridiculous underestimate. After all, every single baptism within the Roman Catholic Church includes an act of exorcism—less explicitly phrased than in earlier years but still very much present. As the Catechism of the Catholic Church instructs (no. 1237), “Since baptism signifies liberation from sin and from its instigator the devil, one or more exorcisms are pronounced over the candidate.” And although it is not actually an exorcism, my own Episcopal Church requires the baptismal candidate or the sponsors to “renounce Satan and all the spiritual forces of wickedness that rebel against God.” So is devil-talk acceptable provided we don’t take it too seriously?

A version of this article appears in the September 27 print edition under the title “Speak of the devil.”