On a summer Sunday morning, bright and windy, I went to the Miracle Centre Cathedral in Kampala. It is the city’s biggest Pentecostal centre, and is run by Pastor Robert Kayanja, the younger brother of John Sentamu, the Anglican Archbishop of York and second in the Anglican hierarchy. The Miracle Centre’s website claims it as the biggest auditorium in east Africa, with a capacity of 10,500 – if so, there must have been 9,000 people gathered there for the second morning service.

I arrived as the first service was ending. Kayanja, handsome and vigorous in an elegant business suit, crisp white shirt with cufflinks and big watch, was striding to and fro in front of his congregation. “It is us who take ourselves into bondage!” he was saying, as cameras projected his image on huge television screens. “Some of us are stuck because we fail to respond to the miracles we have been given! You didn’t hear what I just said! We fail! (Oh, I am preaching good!) We fail! So give ... give ... give and it shall be given.” As soon as he ended, he walked offstage.

In the short break, I was approached by a steward in a yellow jacket, who courteously asked me what I was doing there (I was the only white face among thousands). When I said I was from London he insisted I come to the front for the second service. It began with an extraordinary show, as teenage break-dancers, young soul singers, older gospel singers clad in long gowns and a choir singing in Lugandan, the local dialect, followed each other on to the stage. As singer-preachers took the microphone and sang passionate songs of praise, many in the audience also sang and danced.

After an hour or so, Kayanja reappeared, in a different suit. He made some announcements – including that brunch would be served at the on-site restaurant after the service. Then he segued into a sermon that focused insistently on the creation of wealth and the sin of poverty. At one stage – adopting the pose of a cringing mendicant, bent at the knees with a face twisted in despair, hand stretched out – he denounced beggars. “Beggars,” he declared, “change their face so they look as if they stand between hell and poverty!” All the while, the pastor again punctuated his own sermon with exclamations of “You didn’t hear what I just said!” and “Oh, I am preaching good today!”

The Miracle Centre Cathedral’s charismatic and controversial pastor, Robert Kayanja

He told his congregation that a few weeks earlier he had flown back from the US first class (“the only way to do it”) and landed in Nairobi to change planes for the 50-minute flight to Entebbe, Kampala’s airport. In Nairobi, Kayanja learnt that he was not booked first class for the final leg of his trip. Angered, he had summoned a manager. Kayanja then described a scene that ended with him triumphantly securing a first-class seat. I wondered, as the story unwound, what point he could be making to an audience which, though certainly not the poorest in Uganda, would mostly struggle to fly economy class to anywhere.

Then he answered my unspoken question. “Why did I demand first class? I demanded first class because the Lord sees me as first class. If you see yourself as first class the Lord will see you as first class. But you have to demand it! You didn’t hear what I just said! You have to demand it!”

As the sermon progressed, he told the congregation to come forward with their tithes. Queues snaked up the aisles. Kayanja cited Malachi 3:10 – “Bring ye all the tithes into the storehouse, that there may be meat in mine house.” (Malachi, one of the shortest books of the Old Testament, is much cited. Malachi is stern towards those who do not give a percentage of their income to their preachers; he has become the patron saint of the “megachurch”.)

As he wrapped up, Kayanja told another story – of himself, relaxing on the balcony of his lakeside house. Suddenly an eagle swooped down and seized a fish in its talons – yet still chased away other birds. This, he said, was how they, the church members, must be: willing to catch what was theirs in order to fulfil their potential, achieve wealth and serve their personal goals. If it meant leaving behind others, so be it.

Again, as soon as the service ended, Kayanja strode off. I had seen people give what seemed like substantial sums to a church whose leader flaunted his wealth, and who promised they could be rich like him – richer, even, the more they gave. They had responded as if they were uplifted; saved. As people in Britain who were Nonconformists did decades ago, and as tens of millions of Americans, Latin Americans and Koreans do now, they had given money to a church that gave them in return the belief that they would go to heaven: more, that they would achieve earthly health and wealth.

. . .

Those of us who live in regions such as western Europe, where the observance of the once-dominant religion has been ebbing fast, often fail to notice that religious belief is growing quite rapidly. The World Christian Database shows that the proportion of those attached to one of the four big religions – Christianity, Islam, Buddhism and Hinduism – has risen from 67 per cent in 1900 to 73 per cent in 2005. By 2050, it’s likely that 80 per cent of the world’s population will believe in one or other of the systems proposed by these faiths.

The Miracle Centre Cathedral, the largest auditorium in east Africa

Christianity is the leader, accounting for 33 per cent within 2005’s 73 per cent figure. Within Christianity, Pentecostalism – the “born again” churches – spearheads growth. The image of these as Texas megachurches is not wrong, but it is far too limited. There are six million Pentecostalists in the US – but 24 million in Brazil. In Nigeria, the Redeemed Christian Church of God (RCCG) has grown from a storefront in Lagos half a century ago to a church that lists more than 300 centres in the British Isles, half of them in London. In the US, it claims roughly the same number.

Many of the themes of the RCCG echo those of pastor Kayanja – including the stress on worldly success, and on efficiency. Sermons and uplifting messages from one of the church’s leaders are signposted: “from the President’s desk”. Stress is put on achieving one’s full potential – here and now. The same is true, thousands of miles north, of the Word of Life Church in Uppsala, Sweden, where pastor Ulf Ekman built a megachurch quite alien to Swedish Lutheran traditions. It in turn has founded branches all over the former Soviet Union.

Ekman is close to the Texan televangelist Kenneth Copeland, of the Word of Faith movement, whose “Prosperity Gospel” – like that of Kayanja’s – embraces self-enrichment and (in his case) the possession of a £10m Cessna executive jet. Copeland is, in turn, a disciple of the late Kenneth Hagin – the figure seen as the guru of the enrichment doctrine – who died in 2003. In a tract entitled “One word from God can change your finances”, Copeland cited John 3:2 – “Beloved, I wish above all things that thou mayest prosper and be in health, even as thy soul prospereth” – to argue that “as the seeds of prosperity are planted in your mind, in your will and in your emotions ... they eventually produce a great financial harvest”.

Pentecostalism is not just a worldwide movement: it is a flexible, loosely linked and hugely successful multinational “business”. David Martin, emeritus professor of sociology at the London School of Economics, who has studied the phenomenon, argues that “this is not now a movement which simply radiates from America. Many of these pastors are global figures, constantly travelling, setting up churches, preaching to vast audiences. They are a kind of global intelligentsia: and – this is central – these are modern people. They use modern media, they provide good entertainment, they create megachurches which are all-embracing institutions: a world in which you can live.”

This worldliness co-exists, in ways which both the irreligious and the established religions find deeply unsettling, with a belief in a universe that has much in common with Dante’s Inferno, a place peopled with devils and sinners. This is as true in the US as in Africa: in 1933, at the age of 16, Hagin said he died three times and glimpsed the fires of hell; and in Kampala, I found a man who had come to God the same way.

This man’s name is Peter Sematimba, and I met him in his spotless, well-ordered and luxurious office in a suburb of the capital. He is a radio station owner, entrepreneur, landowner and sometime candidate for the mayoralty of Kampala. The lighting was soft, the desk burnished; two samurai swords rested on a stand beside the computer screen. Sematimba studied medicine for a few years in the US, and speaks slightly American-accented English, with a sprinkling of American slang.

Sematimba believes that God is love. But he also believes that God is, too, a psychologist, a consultant and business partner. It has been, for Sematimba, a profitable belief, one that he said he came to only after undergoing an experience of death. Not near death, he said, but death – twice.

He told me that one evening he was relaxing at home, when lightning flashed and thunder rolled. He felt as if he were being dragged downwards – “This was crazy stuff! I was really suffering and freaking out!” He knew instantly that something supernatural was happening. “I always thought it [being born again] was an exercise in failure, I had seen so many Christians who were really poor.” Yet there he was, in great pain, suspended above a sea of molten lava, which he knew to be hell. At that point, he knew he had died. He experienced a kind of splitting of the soul, then died once more – and knew that if he died again, “that was it”. He called out: “Jesus, if you save me I will believe in you!”

“After a while,” he said, “God must have said: OK! OK! The kid really believes” – and he was pulled back from the brink of hell.

“So I began to have a very realistic relationship with God. I said to God: Listen, if I am going to have a relationship with you for the rest of my life, I must really get to know you. I said to Him: You made me to love money; good food; aeroplanes – and I hope to have my own one day. Why? And God said: Why do you ask? I said: Because there are so many of your followers who are poor and smelly. If you tell me to be poor, that’s OK – but if you tell me it’s OK to be rich, then I will fall in love with you!”

Sematimba said that he had a series of conversations with God (and which, he said, continue). “I said to God: I’m intrigued by where we’re going. But I’m going to test you on this, God. I’m a practical man.” He said that as a test he wanted to heal people – so he went looking for the sick. “Man, there was no one! None of my friends were sick.

“Finally I found a friend with a headache. So I put him in a little corner and I put my hands on his head – I guess that was the way to do it! – and said, Father, your words say this is possible: I declare this man to be healed, your words can’t fail. And the headache was gone, immediately. And we were both scared. I said, Oh my God, it works! So I kept looking for sick people, and I cured them.” When I spoke to him – a Sunday – he said he had cured 17 people at a meeting that same day.

Sematimba was mentioned to me by several people as someone to watch. He has tried to achieve political office, and his media and other enterprises are, he said, making him rich. He sees his religion as a gift from God, as a means of helping humanity and as an aid to enrichment. To one brought up in a society where ministers and priests are expected to live modestly and where Christianity is presented as at best ambiguous about wealth, Sematimba and Kayanja are exotics.

. . .

Congregations at the Miracle Centre and other megachurches are encouraged to donate a percentage of their income as a ‘tithe’

The Pentecostalist movement has gathered to it large numbers of professional people. Barbara Kaija is deputy editor of the largest daily in Uganda, the pro-government New Vision. A pile of management textbooks rested on the desk in her pleasant, air-conditioned office. Outside, in the newsroom, the Sunday edition was being put together in desultory fashion – a TV screen was showing a game in the English Premier League, which is closely followed in Uganda.

Kaija had been Anglican but found the religion tepid and unconvincing, and was then born again. She attends both Anglican as well as born-again services. “This is African worship,” she said, smiling a little at my questions. “There’s singing and dancing and crying on the Lord. The regular churches had lost touch with the power of God: in the born-again churches, in the singing of the hymns, you feel the atmosphere of the Holy Spirit.” There were, she admitted, some bad pastors, but she said much alleged corruption was “just a question of bad management”, and that “what troubles me is that some of the press seeks to put them all down. The devil, you know, can counterfeit a pastor, even a whole church.”

I next saw her, with her husband, at pastor Kayanja’s service, and when Kayanja called for a response, the couple stood and waved and danced with the rest of their co-religionists – leaving me with a vague feeling of disappointment, as if they had both stepped out of a professional, rational, world into one in which rationality had been surrendered. (Since I met her, Barbara Kaija says she has left Kayanja’s church.)

This ability to manoeuvre in two mental registers is a constant feature with Pentecostalists: the Sussex University anthropologist Simon Coleman noted, in a 2006 essay, that pastor Ekman of Uppsala might reply to his critics by “deploying what appeared to be a broadly civil discourse, and then provide far more spiritually radical elements ... in sermons”.

Spiritual radicalism is the movement’s essence, as is charisma. Every successful pastor must have this: the ability, day after day, to hold the attention of actual or television audiences by the force of personality and display of emotion. With that charisma, especially in churches where wealth is lauded, go allegations of corruption. Many of the US pastors, including Copeland and Hagin himself, have been subject to allegations – and these have been made in Uganda, too.

The local burr under the Pentecostal saddle comes in the shape of pastor Solomon Male (pronounced mal-eh). I had been told that he was making waves, and he is – to the point where he believes his life is in danger. I found him in a shop-front office near the centre of Kampala. He was tapping on a laptop, with half-a-dozen people crammed into the tiny room, some of whom he shooed out to accommodate me. Pastor Male, a string-thin man in his late forties, has acquired something of a following.

Nearly 500 years ago, Male reminded me, Martin Luther had launched himself against the vice, luxury and corruption that he saw among his brother pastors. His 95 Theses nailed to the door of a church in Wittenberg in 1517 had been written in anger at the sale of “indulgences”. Male believes this is comparable to what is happening now among some of his brethren, and indeed sees himself through a Lutheran prism. “The man who stood against the evil in the church then was Martin Luther, because he was against the selling of worthless objects which were to save you from hell. The moment he started the Protestant movement, it gave hope that when something is wrong, there is the possibility of setting it right.”

Though a severe critic, pastor Male is a Pentecostalist in his ability to move between registers. At one time, he is rationally severe on corrupt preachers; at another, as willing as they to point out witchcraft – as when he claims that a witch came from Ghana in former president Idi Amin’s time to help to destroy the born-again faith (Amin, a Muslim convert, banned and slaughtered Pentecostalists).

Male’s allegations are that many pastors have devoted themselves to getting rich through a system that tithes to them at least 10 per cent of their congregation’s income. He accuses some of milking funds intended for orphanages; of selling plain water as holy water and olive oil as a divine balm. He loathes homosexuality and says that pederasty is rife in the born-again churches that he says are controlled by the devil. He offered no documentary evidence of these charges, but said they came from the testimony of those who were or had been members of churches in which such practices went on. When I put some of his charges to Barbara Kaija, she smiled and said: “There are always people making such allegations.”

. . .

After I had spent about half an hour with Pastor Male, a woman in her thirties came in and sat down: she had, I think, been summoned by one of Male’s aides. Her name was Frances Adroa; she has Aids, and is one of the pastor’s prize exhibits in support of his apostasy. She alleges that senior pastors at a Kampala church that she joined in June 2005 took her car from her, promising in return to cure her Aids. In an affidavit she swore in April 2007 to the chief magistrate’s court, she said her car was handed over to the church’s leadership on July 11 2005.

Her Aids was not cured. She demanded the car back and it was returned – badly smashed up, together with a demand that she pay £700 to defray the costs of improvements that the church said it had made to the car. Adroa says she has not lost faith in God, but agrees with Male that many pastors are witches or indeed the devil.

Male’s Pentecostal Lutheranism is a much more minor – indeed, barely heard – argument than the opposition and criticism that is faced by the born-again pastors in rich societies. According to David Martin, the movement has a dual strength the world over: it appeals to the upwardly mobile, and it appeals to what used to be called the deserving poor, who wish to adhere to a discipline, as much personal as religious, which will lift them from poverty. “It appeals to those on the margins, and those who are moving up,” Martin says. “There is an explicit stress on being faithful; eschewing drink; being well ordered in your life. God’s grace, which will benefit you materially, must be won, and there are stern reasons for failure – as ‘God is testing you’; or ;You haven’t done enough’; or ‘You’ve done it wrong.’ And, as it did with Methodists and others before, it works: if you discipline your urges, you tend to do better.”

When I left Sematimba’s radio station, his Kalashnikov-armed guards found me a boda boda – a motorbike taxi that is the best, if an insecure, way of travelling around the choked city. My taxi driver was called Jackson, and on the back of the seat on which I sitting was a stencilled slogan saying “God is Love”. Knowing I had seen Sematimba, he said: “That is a righteous man!”

“Rich, too,” I shouted from behind his un-helmeted head.

“Yes!” he said, “That’s right. He is very righteous!”

John Lloyd is an FT contributing editor