'A man was driving his car along a mountain road. The car went over a cliff. The man was thrown out but clutched on to a twig. Then, discovering that he was still alive, called out: 'Help, is there anyone up there?' A voice from Heaven said: 'Yes, my son. Do you trust me?' And he said: 'Yes.' 'Let go of the twig and I will catch you at the bottom.' And he looked down. A silence followed, then: 'Help, is there anyone else up there?' '

The congregation at Cape Town's St George's Cathedral, the seat of the Anglican Church in South Africa, cracked up laughing. It was 6 March 1990 - barely a month after the release of Nelson Mandela and the occasion was a thanksgiving service. The preacher was the man Mr Mandela had just displaced from his position of pre-eminence in the resistance against apartheid, Archbishop Desmond Tutu.

The archbishop could not have been happier. The long awaited opportunity had come to abandon his interim political leadership, lower his profile and do the normal things that become a priest. Gratefully he reverted to his appointed task of justifying the ways of God to man. Now he could tell his flock that, despite all the evidence, God had vindicated his flimsy twig of faith and South Africans could, at long last, proclaim the beginning of the end of apartheid.

In what might have been interpreted as his final bow from the political stage, on 9 May this year he introduced Mr Mandela, freshly sworn in as President, to a rapturous crowd from the balcony of Cape Town's city hall.

Diminutive but drawing on oratorical skills unmatched by any South African, he captured the apotheosis: 'Friends, this is the day for which we have waited for over 300 years. This is the day of liberation. This is the day of celebration. . . . We of many cultures, languages and races are become one nation. We are the Rainbow People of God. And one man embodies this new spirit of reconciliation and unity. One man inspires us all, one man inspires the whole world. I ask you: welcome our brand-new State President, out of the box, Nelson Mandela]'

Those words held a few ironic echoes last week when Archbishop Tutu and President Mandela suddenly ventured into a most unseemly war of words. It would have been no less of a shock to learn that the Pope had been in a slanging match with Mother Teresa. Mr Mandela, in a speech, accused the archbishop of an irresponsible inability to resist temptation and the archbishop replied that Mr Mandela had not only acted in a manner beneath his stature, he had been economical with the truth. The row concerned a statement Archibishop Tutu made about highly paid officials in the new government having 'stopped the gravy train only long enough to get on it'.

At Bishopscourt, the lavish Cape Town residence of South Africa's Anglican primate, Archbishop Tutu, 63 this week, appeared neither hurt, battered, nor bowed. Lying back in his chair, shoes off, purple-socked feet resting on a stool, he chortled when asked whether he and the President had kissed and made up. Indomitably good-humoured, he found more than 30 occasions to laugh out loud during the next hour. He tittered, he shrieked, he giggled, he guffawed, he chuckled, he clutched his sides. The spectacle would have been ludicrous were it not for the wisdom and sincerity of his words. The archbishop is a Nobel peace laureate, he has more than 50 honorary degrees, has met more heads of state than he can remember, is one of the world's most famous people, has seen God, but is the enemy of pomposity.

So, had they kissed and made up? 'Oh yes]' he laughs. 'Oh yes. I called him on Wednesday morning, and then I called him again and eventually, in the evening, he called me back. And I said, 'Why are you attacking me, man?' ' The eyes were bright, the tone mock indignant. 'And he laughed]' At which the archbishop himself, in his mirth at the recollection of the exchange, almost fell off his chair.

So they remained friends? 'Of course. He tells me things - private things. I'm incredibly fond of him and I'm also in a way in awe of him, really: his serenity, his presence, magnanimity. You know, it's not put on. I don't think if you squeezed him you'd get one drop of bolshiness out of him.'

As an example of what Mr Mandela had given the country he quoted a recent editorial in the Citizen, a newspaper that was in effect the mouthpiece of the government during the 1980s, which used to deride him as, among other things, 'a religious superstar'. 'Can you imagine reading the Citizen (he chuckles) and the Citizen saying (he's laughing so hard now he battles to complete the sentence) 'Mandela we need you]' ' He has collapsed now, overwhelmed by the triumphant implication of a newspaper that for so long slavishly supported apartheid telling its white conservative readers that President Mandela is the best thing South Africa has ever had.

Why did he think Mr Mandela had lost his cool, his serenity, and attacked him? 'Yes, it was so unlike him. At no point does he normally denigrate anybody, which is why this attack on me was so odd. Why? I don't know . . . but well, it's good to know he's human.'

Friends or not, as the gravy train episode showed, Archbishop Tutu does not intend to let his adulation get in the way of moral vigilance. How did he define his political role today? 'As it comes]' (More laughter.) How does it come? 'We want to be part of the healing process because everyone in this country has been traumatised. We want to be the instruments of the truth and part of it is having to say to these guys: 'Where is the idealism?' Partly our beefing against them is precisely because we don't want them to fail, man. We've invested so much in helping them to get there.

'Because you see what the world is seeing in South Africa is a little goodness. Goodness does prevail ultimately. These seem almost like slogans but the world is thrilled because the world ultimately warms to goodness - and that is why they are warming to Mandela.'

What were the lessons for the world, for Bosnia, for Northern Ireland, from the South African experience?

'One: you've got to have the actors. It's not good if you don't have people who are ready to put their lives and reputations on the line. Mandela has done that, and De Klerk. Second, we have been prayed for, you know. This is a miracle. It is not of our doing. We've been on the intercession list of the world for a heck of a time. Yah, man, and it works. It works]

'Well, of course, Northern Ireland has had a concentration of prayer, too, but those involved there must know that if they are not prepared to compromise they've had it. Two years ago in Dublin I said if you don't have something that is perceived to be inclusive you've had it. And the British government got angry because I said if you begin putting preconditions you're not going to make first base, man. So they must be ready to compromise, to be accommodating. I'm saying this of all of them: you're not likely to get your most ideal position but you're going to get very close if you are ready to ensure that the other person has something that they too can show their constituency.'

The miracle having taken place in South Africa, how did he see the future? The gravy train remained a worry. 'You know, it's painful because one loves so many of them and one knows how deeply committed they have been to the struggle. You're hurt because they have succumbed so quickly to these blandishments - six months]'

But he chuckled even as he said this, as if he expected his friends the government ministers to mend their ways. For South Africa, he believes, is blessed. 'We will succeed and the reason why is not because we're smart, it's because God wants us to succeed for the sake of the world.

'Dullah Omar (South Africa's justice minister) is an example. Remember the Third Force tried to kill him, by switching his heart pills. This man is sitting down now drafting legislation for amnesty so that the people who tried to kill him might be forgiven. We are this beacon of hope for the world because we are so improbable.'

'The Rainbow People of God: South Africa's victory over apartheid' by Archbishop Desmond Tutu (with a foreword by Nelson Mandela) will be published by Doubleday later this month.

(Photograph omitted)