Maradona was a great footballer, and could be equally inspiring as Argentina's new coach. But does that explain why 120,000 people literally worship him? Jonathan Franklin gets baptised in the Church of Maradona

The congregation screams so loudly that I can't even hear the priest, even though I am in the front row. As the service gets under way, the hundreds of faithful recite their own unique version of The Lord's Prayer:

Our Diego

Who art on earth

Hallowed be thy left foot

Thy magic come,

Thy goals be remembered

The lights dim, and six men in white tunics walk up the aisle. Each member of La Iglesia Maradoniana - the Church of Maradona - has the great footballer's number 10 on his back. Up front, an altar boy holds aloft a bloody football. It looks as if it has been tortured. Blood drips off its leather hexagons. Coils of barbed wire crown it. Behind the altar is a huge portrait of the man whom the crowd have come to worship - Diego Armando Maradona.

The man behind me wears a T-shirt emblazoned with the words "The Pope is German, but God is Argentine" and a stylised Maradona running at full speed, preceded by a football. The room is hot, sweaty and smells of beer - not surprising, as everyone has a glass in their hand. As we gather around a small stage that pays tribute to the glorious goals of the blessed Diego, men's voices echo as they chant:

He was crucified, killed and tortured

Suspended from the pitch

They cut his legs

But he returned and his magic spell was reborn

A man begins to cry, the entire inside of his right arm covered by a tattoo spelling out DIEGO. He hugs his son, a boy of three or four who stares bug-eyed at a 2-metre-high wooden church that is at the centre of the stage. Inside stands a statue of you-know-who, head held high, hand over his heart. With the Argentina shirt on his chest and his foot planted atop a Puma football, Maradona looks invincible.

The Iglesia Maradoniana does not yet have its own building. It is a travelling display of love and affection, whose icons and statues visit all corners of Argentina. "This procession is important - it demonstrates how unconditional we are to Diego," says Alejandro Veron, who helps to run the official website. "Our religion is football and, like all religions, it must have a god. We will never forget the miracles he showed on the pitch and the spirit he awoke in us, the fanatics."

Now, on a hot evening in Buenos Aires, the priest signals to me and speaks the words I have been waiting for: "And now your baptism."

I walk up to the stage, take off my top, and the crowd screams as I slip on the No 10 shirt and remember my rehearsals. Just one shot. Do it right, I tell myself. The baptism ceremony aims to recreate the sacred moment during the 1986 World Cup quarter final in which Maradona scored his famous mano del Dios (hand of God) goal by swatting the ball into the England net with his fist. Match officials stuck with a poor angle assumed Maradona had used his head, but replays clearly show Maradona punching the ball away from the England goalie, the startled and then indignant Peter Shilton. At a press conference after the game, Maradona would not admit his hand had touched the ball. "The hand of God" sent it into the net, he claimed.

I move over to a life-size poster of Shilton jumping at Maradona. In this version, Maradona and the ball have been Photoshopped out of the frame. This is where the baptism ceremony begins. I prepare to leap.

As the ball is tossed in, I jump, trying to shield my hand with my head, then "pow!" I punch. It works! My re-creation is worthy of a certificate and now I am signed into the register, an official member of the Church of Maradona.

Today, October 29, is a special day for the congregation. It is their Christmas Eve, the day before their god was born. And so 500 are bunched tight near a Christmas tree decorated in the white and blue of Argentina's national colours. The branches are covered in smiling photos of Maradona. If you look closely, you can see that he is holding his holy shroud - the Argentine national strip. It's doubly appropriate this year, with Argentine football officials announcing that Maradona will be the new national coach. It is a remarkable comeback for a former drug addict with some spectacular scandals to his name. A poll for Clarin newspaper in Buenos Aires suggested that 74% of Argentine public did not want him to get the job.

The members of the Church of Maradona naturally see this as heresy. Who better than their god to lead them to the World Cup finals in 2010?

"We have been with Maradona during the darkest moments, and now we are here with him - how can we not be celebrating?" wrote Jose Caldeira, the author of La Iglesia Maradoniana, a book chronicling the church's first 10 years.

"The darkest moments" is code for Maradona's long affair with cocaine. For almost his entire career, Maradona snorted his way to both fame and international disgrace. In good times he scored glorious goals. In bad, his body swelled up like a whale's and he was rushed to the emergency room.

His admirers even put a positive spin on that. "He admitted that he was a coke addict. With all the cocaine he did, a normal person's body would not have stood it. A mere mortal would have died," says Mariano Israelit, whose job at the Fox Sports channel has brought him into the footballer's inner circle. "Diego is in another dimension. He says and does many stupid things. He makes a mistake and he is pardoned because he is a myth, a living legend."

In one infamous episode, Maradona fired a rifle at journalists and photographers who had staked out his home. Then he was photographed naked, snorting coke, surrounded by nude women. That scene took place in Cuba, in a clinic where Diego was supposedly being treated for his addiction. Since then, however, he has clawed his way back to respectability. And it is that fighting spirit, that passion for victory, that makes Church of Maradona members so loyal.

Fans have come to Buenos Aires from the US, Brazil, Denmark and Italy to celebrate the church's 10th anniversary. Some take pictures; others simply toast their god. A pile of gifts and tokens piles up - old photographs, sports cards, even an oil portrait of Diego with brushed curls and a yellow halo. The Maradona Bible lies near the altar - a worn copy of Maradona's bestselling biography Yo Soy El Diego (I Am Diego).

Off to one side is the Diego tattoo competition. Who has the best likeness of the almighty inked on to their body? On stage, the finalists of the "Who Knows Most About Diego?" competition are rattling off the colour of their god's first car and the birth date of his second child.

Like the druids at Stonehenge, Maradona's disciples have their own sacred dates. Their year begins on Maradona's birthday, October 30, and this is not 2008 but 48AD (After Diego). The church also has its own ten commandments.

Does all this hero-worship worry established religions? Not if Father Marcial Cabon, of Buenos Aires's Madre del Dios congregation, is any guide. "He's not a god at all," Father Cabon later tells me. This Catholic priest is far more interested in Maradona the coach. "He is going to be a winner," he says. "And if we play England, he will lead us to victory."

Back at the church, Jose Gabino, a tired-looking 51-year-old, tells me that he used to dream of being like Maradona. "In good or bad he tells it like it is." His eyes well up and he proclaims: "Diego is sent from above. God does not speak to Maradona, he speaks to God." And no, Gabino is not drunk.

"Are you worried that this movement might die out, just last a single generation?" I ask him.

The answer is sitting next to us.

"I named my son Diego out of admiration," says Gabino, pointing to the 17-year-old. "One fan dies, a hundred are born."

Since its founding in the city of Rosario, the church has grown from a small group of friends to a worldwide presence. On some days more than 500 people have asked to join. Veron puts the current membership at around 120,000. Even professional football players have flocked to the church. Ronaldinho begged to have his own Church of Maradona T-shirt, and Carlos Tevez of Manchester United and Lionel Messi of Barcelona are card-carrying members. They're not quite as devout, however, as Lionel Diaz, who was one of the church's original members. "My son is one and a half years old, and he has learned that when I say 'Ole! Ole!' he should respond 'Diego! Diego!' He can say three words: Mum, Dad and Diego." Diaz's five-year-old daughter, meanwhile, "can recognise Maradona no matter what. I show her pictures of him with a beard, without a beard, with sunglasses and without - she never fails."

As the service continues, video screens show Diego's best goals, Diego's most famous interviews. Here he is with Fidel Castro, and again turning the entire England team inside out during the 1986 World Cup.

When the clock strikes midnight, Maradona's birthday arrives and a building-rattling party begins. Waiters pass trays of champagne, a toast is made. Then a phone rings and the crowd falls silent. It is God, live by speaker phone.

"Thank you for giving me so much affection and gathering on a day like my birthday," says Maradona. The crowd erupts. Tears flow. Beers flow. The crowd sings back: "Champions yet again . . . Again like '86.""What you're singing is the dream I have inside me," says Maradona. "God is going to be with us."

As far as his compatriots are concerned, of course, God is already with them. Diego Maradona is unconditionally, unbearably Argentinian. As a player in the national team he even slept in an Argentina shirt. During the 1990 World Cup, with his ankle swollen to the size of a grapefruit, he still gave 100% on the pitch. Maradona was adored because he played not for fame nor fortune but for his nation. Working-class fans above all recognised him as one of them, this boy from the slums of Villa Fiorito, whose Sunday barbecue was as likely to feature cat as cow. When Maradona was sold to Barcelona, his fans at Boca invaded the airport, broke through security and lay down on the runway in an attempt to prevent his plane from taking off.

"The Argentinian is passionate, temperamental, bloody," says Hernan Amez, one of the three men who founded the church. "Maradona demonstrates that persona on a football pitch. He is the one who never gives up.

"Each of the guys here has a special Maradona moment," he continues, as a waiter pushes through the crowd with a tray of champagne. "Maybe it is a memory of a brother who is not alive any more, or a friend who is no longer around. Maradona makes us remember those moments - they live in our heart. It is impossible to separate him from these emotions. Maradona makes us feel so strong. That is why we love him as much as a god."

The Church of Maradona's ten commandments

1. The ball is never soiled.

2. Love football above all else.

3. Declare unconditional love for Diego and the beauty of football.

4. Defend the Argentina shirt.

5. Spread the news of Diego's miracles throughout the universe.

6. Honour the temples where he played and his sacred shirts.

7. Don't proclaim Diego as a member of any single team.

8. Preach and spread the principles of the Church of Maradona.

9. Make Diego your middle name.

10. Name your first son Diego.