AS HAS been noted many times over the past week since his death, Nelson Mandela's leadership of South Africa after the ending of apartheid and his release from 27 years in jail was an outstanding example of forgiveness and reconciliation. Less prominent in the tributes, however, has been any mention of the way that this owed much to the Christian faith that he held throughout his life.

As Mandela once remarked to his close friend and former fellow inmate on Robben Island, Ahmed Kathrada: "I never abandoned my Christian beliefs."

Yet he never said much publicly about them. In a letter to his daughter Maki from his cell, he wrote: "As you know, I was baptised in the Methodist Church and was educated in Wesleyan schools - Clarkebury, Healdtown and at Fort Hare. I stayed at Wesley House. At Fort Hare I even became a Sunday- school teacher. Even here I attend all church services and have enjoyed some of the sermons . . . From experience, it's far better, darling, to keep religious beliefs to yourself. You may unconsciously offend a lot of people by trying to sell them ideas they regard as unscientific and pure fiction."

It was Mandela's mother who passed on the faith to him. She was one of four wives of a Thembu chief, and uneducated, but a devout Christian. She had Mandela baptised, and sent him to a Methodist mission school at the age of seven, where his teacher gave him the name Nelson.

Two years later, his father died, and the regent and chief of the Thembu people became his guardian. Mandela went to live in the royal household, where he was given a Christian upbringing with the crown prince, going regularly to church, learning about the contributions that missionaries had made to the education, health, and the general well-being of black Africans. It was after this that he attended Wesleyan schools, and then the South African Native College (a Christian foundation that was later renamed the University of Fort Hare).

In 1941, at the age of 23, Mandela arrived in Johannesburg to train to be a lawyer. Three years later, he joined the African National Congress to work for a fully democratic South Africa, as the black people had no vote. The ANC used only peaceful methods of protest at that stage, as it followed the ideas of Gandhi, who had campaigned non-violently for fellow Indians against racial discrimination in South Africa early in the 20th century.

After the Afrikaner Nationalists came to power in 1948, and imposed apartheid, anyone criticising its laws of segregation could be arrested as a Communist. Mandela soon became deputy president of the ANC, leading peaceful protests against the apartheid laws, and being jailed briefly. He also qualified as a lawyer, and set up the first all-black law firm with Oliver Tambo, helping to get opponents of apartheid out of jail.

In 1955, however, Mandela was so angered by the government's forced removal of the black people from Sophiatown, in Johannesburg, that he said publicly that peaceful protest was not effective. For this, the ANC reprimanded him.

Then, in 1960, two events occurred that made Mandela decide that the principle of non-violence must definitely be changed. The first was the shooting at Sharpeville of 69 peaceful demonstrators, in a protest against the pass laws, by inexperienced policemen. The second was the banning of the ANC, after Sharpeville. This meant that even peaceful protests under the auspices of the organisation could result in jail sentences.

Many of those in the ANC Executive were nevertheless strongly opposed to the use of violence, above all Chief Luthuli, the president of the ANC, who was a Methodist lay preacher.

While there exists the theory of "just war" in Christian thought, there is not an explicit one of "just revolution". Mandela recounts in his autobiography, Conversations with Myself (Macmillan, 2010), how he was once challenged on this point when he was in Pollsmoor Prison in 1984, and was visited by two Americans from the Washington Times, who seemed intent on finding proof that he was a Communist. When they failed to do so, they attempted to show that he was not a Christian by asserting that Martin Luther King had never resorted to violence.

Mandela countered that Dr King's situation had been very different, as non-violent protest was a protected right in the United States, whereas South Africa had inequality enshrined in its constitution, and police fired on unarmed protesters.

He writes: "I told them I was a Christian and had always been a Christian. Even Christ, I said, when he was left with no alternative, used force to expel the moneylenders [sic] from the temple. He was not a man of violence, but had no choice but to use force against evil."

The problem with this argument, however, is that Christ's action did not cause fatalities. Mandela also asserted in his autobiography that Gandhi's situation in India was different from his: "In India, Gandhi had been dealing with a foreign power that ultimately was more realistic and far-sighted. That was not the case with the Afrikaners in South Africa."

THE Dutch Reformed Church expressly taught that the blacks were inferior to whites, which meant that it was less likely that the latter would be converted to their victims' cause, as Gandhi had thought that they ultimately would. What was needed was for the Calvinist Church worldwide to pressure its members in the Dutch Reformed Church to realise that its teachings were, in fact, unChristian. Ultimately it could be argued that Mandela was faced with a situation that could have been avoided if all the Christian Churches, Catholic and Protestant, could have condemned the Dutch Reformed Church and supported the anti-apartheid movement by urging their congregations to disinvest in any bank or company that had financial interests in South Africa. This would have dealt a blow to the country's economy, and would indeed have resembled the anger of Jesus turning over the tables of the money-changers.

Eventually, at a secret meeting held overnight in Durban in 1961, Mandela persuaded Chief Luthuli to agree that an organisation be set up as the military arm of the ANC, but separate from it. This would not jeopardise the legality of unbanned organisations that supported the ANC, but not the use of force.

The organisation was called Umkhonto we Sizwe (MK for short), or "The spear of the nation"; Mandela was to be its Commander-in-Chief. The form of violence to be used was sabotage, since, Mandela said, it did not involve loss of life, and would therefore make reconciliation between the races easier afterwards. Realistically, however, the loss of lives was inevitable, and did take place.

In December 1961, the MK started its campaign, using leaflets distributed over the country, and bombings of power stations. Mandela, meanwhile, secretly left South Africa, to ask governments in Africa and the West for support, and to undertake military training. On his return in 1962, he was arrested, and eventually sentenced to life imprisonment, with other members of the MK, for sabotage. He remained in jail for 27 years.

We cannot know for certain whether Mandela's use of violent protest made a significant contribution to the ending of apartheid, but we do know that it was Mandela's desire for reconciliation that enabled him to lead South Africa to democracy peacefully.

His setting up the Truth and Reconciliation Commission with Archbishop Desmond Tutu and others, to investigate the truth about alleged human-rights abuses, and to attempt to dispense restorative justice; his calming the nation after the assassination by a white supremacist of Chris Hani (his probable heir apparent), by pointing out that it was an Afrikaner woman who called the police and gave them the assassin's car number; his inviting his former prison guards to his presidential inauguration; his giving a lunch for the wives and widows of the leaders, both black and white, of the apartheid struggle - these and other such acts were all part of a distinctive desire for reconciliation, which probably prevented outright civil war in South Africa.

Before his imprisonment, Mandela used to enjoy attending Zionist Christian Church services, "with their Bible-thumping ministers", as he later noted. At a church conference in 1992, he described the founding of this Church, in 1910, as "an important act of the oppressed to resist the theology of submission".

In an address to the Easter conference of the Church two years later, Mandela spoke of the "Good news borne by our risen Messiah, who chose not one race, who chose not one country . . . who chose all mankind."

He referred to the challenge that the ANC had faced, when the government of the 1960s had established a near-"totalitarian grip over the country", and argued: "I remain convinced that it was our willingness to rise to that challenge that paved the way to our present circumstances."

Whatever the questions that may be raised about his use of force, Mandela squared them with his conscience, which is regarded by some as that of a Christian freedom-fighter.

More importantly, in a world of bloody cycles of revenge, he has shown what a human being can achieve through forgiveness. It is because of this that the world has made him into an icon through which his faith may be glimpsed, despite his discretion.

Dr Audrey Wells is Honorary Research Associate in the History department of Royal Holloway University of London.