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 to be held 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.

While the Catholic Church is best known for performing exorcisms, depicted in Hollywood films like The Rite, which starred Sir Anthony Hopkins, the practice exists in other denominations of Christianity.

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 round table meeting on how to perform exorcisms will bring together clergy from the Catholic, Anglican, Lutheran, Greek Orthodox and Pentecostal Churches.