Catholics join up with other denominations to battle Satan
It sounds like the start of a joke - a Catholic, a Lutheran and a Protestant walk into a room to talk about the devil - but a conference on exorcisms this week in Rome will be no laughing matter.
For the first time, representatives of the main Christian faiths will come together to trade tips on casting out demons and combating the malign influence of Satan.
The meeting will be the culmination of a week-long training course for exorcists which began on Monday at a Vatican-affiliated university, the Ateneo Pontificio Regina Apostolorum.
The dark art of performing exorcisms may seem archaic, even absurd, to non-believers, but the Catholic Church insists that the presence of the devil is growing all the time, due to the increasing secularisation of society, loss of faith in God and the easy access provided by the internet to black magic and the occult.
The meeting will bring together clergy from the Catholic, Anglican, Lutheran, Greek Orthodox and Pentecostal churches.
"This is the first time that different denominations have come together to compare their experiences on exorcisms," said Pedro Barrajon, a Spanish priest and professor of theology who is one of the meeting's organisers.
"The idea is to... establish best practices, if you will. The Catholic Church is most associated with exorcisms because of films like 'The Exorcist' and 'The Rite', but we are not the only church that performs them. Expelling the devil goes back to the earliest origins of the Christian church."
When it comes to battling Beelzebub, there are key differences of approach between the denominations.
"The Catholic rite is very structured, whereas some of the other churches are more creative," said Fr Barrajon (61), who claims to have witnessed several exorcisms.
Benjamin McEntire, a Protestant priest from Alaska, was one of the 240 clergy from five continents attending the conference.
"I'm here to understand the Catholic perspective. We are fighting the same enemy in the name of the Lord," he said.
Atheists and agnostics may scoff at the idea of people being possessed by demons, but the Catholic organisers of the conference insist the phenomenon is real.
Just as in horror movies and novels, victims really do speak in strange tongues and vomit objects such as nails and shards of glass, they claim.
"One of the signs of demonic possession is that people speak in languages that they do not know, such as Latin and Hebrew," said Fr Barrajon. "They have supernatural strength and a strong aversion to priests and to sacred objects."
The Catholic Church concedes that the majority of people who say they are possessed are in fact suffering from psychological illnesses and should seek help from medical professionals.
But there is a minority that really are in the clutches of Satan, they claim.
The rite of exorcism consists of prayers and then attempts by the exorcist priest to engage with the evil spirit inhabiting the victim's body.
"It is a battle between the exorcist and the demon. In some cases the exorcism is successful after a few hours, in other cases it takes years," said Fr Barrajon.
The week-long conference on exorcism, which is in its 14th year, is unique.
Seminars to be held this week include 'Angels and Demons in the Sacred Scripture, The Historical Origins of the Rite of Exorcism' and 'The Symbology of Occult and Satanic Rituals'.
"Young people are increasingly attracted to black magic, Satanism, vampirism and sorcery," said Giuseppe Ferrari, a professor of theology and organiser of the course.
The Catholic Church's exorcists have found a firm ally for their cause in Pope Francis, who frequently makes references to the devil in his sermons and public addresses.
Two years ago he said: "He is evil, he's not like mist. He's not a diffuse thing, he is a person. I'm convinced that one must never converse with Satan - if you do that, you'll be lost."