On Easter Monday, April 25th at 9pm, my new special DERREN BROWN: MIRACLES FOR SALE will air on C4. This is hot off the press, so I have no artwork to show you as yet.

This is the special about faith-healing that some of you will have heard about. It has been the most intensely difficult project that I have attempted: to train an ordinary member of the public as a faith healer, then take him out to Texas, the heart of the Bible Belt, and try to pass him off as the real deal. We filmed this at the end of last year amidst concerns that we had bitten off far more than we could chew.

The film we made is driven by a desire to expose what I consider to be a foul and dangerous fraud at the expense of the sick, the needy and the faithful all over the world. It is not a comment on the church, or belief, or even, before some people get upset, the idea that God can or can’t heal. It is about a specific fraud, a greedy trick that has nothing to do with God whatsoever, beyond the fact that his name gets shouted around a lot. We made the show with the involvement of Christians and pastors who had been involved in that particular scene.

No faith healer has ever been able to provide evidence of a single miraculous healing ever having had occurred. Some when pushed have offered a few success stories, but when those ‘healed’ people have been approached, they turn out to be the same as before, worse than ever, dead, or not to have had the ailment in the first place. What does seem to happen, though, is a cleverly-engineered emotional event brings people into a state of hype that releases adrenalin, which acts as a pain killer. People in the audience with low-level ailments that can respond to such pain relief – combined with a huge amount of expectation and a desire to be healed, or ‘close to the magic’ – will commonly find themselves pain-free and step forward when asked to. There then follows, at the larger events, a filtering process where stewards send back anyone with a serious or visible ailment (such as an arm missing) and test the remaining arthritics and bad-back sufferers to see if they can display a convincing pantomime of having been healed (touching toes and so on). There are other tricks to seemingly cure the blind and deaf which I will also demonstrate on the show. These poor people are then brought up on stage in their heightened state to bounce around and think they’re healed while the truly afflicted are left to believe God hasn’t taken much of an interest. It’s very disturbing to see the rows of the seriously disabled on drip machines, in wheelchairs and even hospital beds, ignored and invisible, safely behind the TV cameras’ reach at the big-name events. Or to hear of the chronically afflicted being carried to these rallies around America by families who spend every last penny they earn in hope that the man on stage might channel a little of God in their direction. A wake of despair is left behind by these charlatans, made up of hundreds of thousands of people who receive no healing or only temporary pain relief, and are encouraged to blame themselves for not having enough faith when they find nothing’s improved.

And then there’s the money. This is the hub of the whole operation. The financial motivation seems to be closely linked to something called the Prosperity Gospel, which has to be the most perverse and self-serving piece of scripture-twisting I have ever come across. It was loudly preached by Oral Roberts and made popular in the 90s, and takes the rather lovely idea of ‘sow and ye shall reap’ and re-defines it as a financial incentive. Jesus bestows his blessings in the form of money. How do you get these blessings? You first give money. More than you can afford, otherwise it doesn’t count. Jesus will repay you hundredfold. If he doesn’t, you probably didn’t give enough, or perhaps you have secret sin or not enough faith. And to whom do you give your money? Your preacher, naturally. You might want to read that through again if this logic is something new to you. Not surprisingly, the big name preachers earn far more than any Hollywood A-lister from this system. Proof of the fact that Jesus bestows his blessings in the form of money? The stinking richness of your pastor. Perhaps his fleet of private jets might just convince you. And these donations come in not just from a mesmerised flock gathering twice on a Sunday, they flood in from millions of people on mailing lists which form the backbone of the big business of faith healing. The TV rallies, the crusade events, are all designed to encourage people to sign up and send in a sizeable chunk of their earnings every month. Cash floods in tax-free (for as long as you say it’s a church you are pretty much left alone by the IRS) and is spent on lifestyles that in some cases reach beyond imaginable luxury. People imagine perhaps that the money goes somewhere worthwhile to support God’s work. It’s disheartening watching the sick and the elderly put cash they can’t afford into the donation buckets at these vast crusades when I hear of how one big-name healer spent thousands of dollars after a rally, in said cash, on hotel room service and rent boys.

The healers perform their shows over here too: I recently went to see a couple of the current main men at venues in London and have never felt such a heady mixture of disgust and deep pity. A girl behind me screamed to her friend ‘There’s your proof God can heal!’ as we watched a man climb out of his wheelchair on stage; in her delight, she missed the moment later when he collapsed unhappily back into it once the cameras had been swiftly pointed away from him. At least it was his own chair: another common trick is to quietly stick someone with a bad back into one of the healer’s own wheelchairs to ‘make things comfortable’ for them, so that once they are brought before the crowd, the glistening man of God can command them to rise from a chair they didn’t need in the first place. Praise the Lord.

The project was hugely difficult because a big business like faith healing is almost impenetrable. We tried to speak to those who had worked alongside the current big-name healers, as we knew of a few who had been allowed in the inner circles of trust and knowing the depths of the corruption had eventually turned against it. But these are people who live in fear. They were told for years by their charismatic, ruthless leaders that they lived under a curse and that to leave the clan would result in God ending their lives. Disturbingly, that may not always be too far from the truth: we heard of a couple of witnesses who had been brought to testify against a healer and had died mysteriously of heart attacks the night before the trial. Something dark may be afoot.

There is, as one might hope, a growing scepticism in Britain amongst Christians towards these so-called healers. Although I don’t hide my own lack of religious belief, my repulsion at this scam comes as much from my days as a Christian as it does from simply being a human being observing ego- and money- driven fraud. It was a gruelling journey to penetrate the world of that fraud in the small way we could, with our own particular journey of seeing if an ordinary guy could pass as a real healer. I hope that the ranks of intelligent believers will feel the same concern at our findings as the rest of the viewers.

Easter Monday, 9pm, C4.