His name is J John, he is sometimes seen as Britain's answer to Billy Graham, and will take over a nightclub in East London tonight for a huge carol service - the latest stop in a exhausting tour that will see him give 15 Christmas sermons in 11 days.
J John (his real Greek name, Iouannes Iouannon, is "too much of a mouthful") will be preaching to more than 1,500 people at The Island in Ilford, Essex, where recent attractions have included the all-girl soul group Eternal and the thrash metal band Napalm Death.
Not a clergyman but a full-time preacher living on donations from Evangelical supporters, John, as friends call him, hits the road when the Christmas decorations go up. One year he spoke at 32 carol services in a month, and more than a quarter of a million copies have been published of a small book, What's the Point of Christmas?
Seats are very hard to come by at his carol services, which regularly attract crowds of 1,000 or more. Church buildings are often too small, so local believers book school halls, leisure centres and even unashamedly secular rock venues.
A small, friendly 36-year-old with the enthusiasm of a used car salesman and the patter of a stand-up comedian, John was converted to his born-again faith 20 years ago while at college - to the alarm and disapproval of his Greek Orthodox parents.
"People are more open to what I've got to say at Christmas than at any other time," he says. "We don't live in a country full of agnostics or aetheists - a lot of people consider themselves religious. When they go into hospital, for example, they'll put C of E on their form.
"It's kosher to be religious at Christmas time. It gives me an opportunity to be listened to."
As well as comforting familiarity ("Hark The Herald Angels" is the most popular hymn at his services) he likes to do things differently. Next week in Nottingham he will turn off all the lights during a service and preach in the darkness. "I want to talk about the dark side of Christmas. Abuse in the home. Loneliness. It's hard for people."
John makes no secret of his aim to convert them, even asking believers to leave the service if there aren't enough seats for the others.
"I'm not anti-Santa, or shopping, or all the other things that go with it. I like turkey, tinsel and Tia Maria, but it's wrapping paper. Our problem has been that we've got caught up in the wrapping and missed the present, the real message of Christmas."