Mikhail Gorbachev wrote to The Times in March to remind us of his and President Reagan’s statement in 1985 that “a nuclear war cannot be won and must never be fought”. It was also a reminder of the good fortune of his partially Christian upbringing – no doubt this was one of the reasons that, with Margaret Thatcher, he and President Reagan kept the peace.

He described the secular and the spiritual in his childhood home as “peaceful coexistence”. He lived in the Caucasus during the Second World War, in which his father fought, as his grandfather had fought in the first. The family room had on one side a bookshelf with booklets by Marx, Engels and Lenin. The other corner had an icon and an icon lamp and underneath, on a homemade table, stood the portraits of Lenin and Stalin. Gorbachev’s grandmother was deeply religious but his grandfather was not a believer. Neither his grandparents nor his parents were troubled by this clash of faiths, and both were respected. They left it to the young Mikhail, later a student at Moscow University where he met his wife Raisa, who was reading philosophy, to work out the coexistence on the national arena.

Gorbachev visited London twice, first in 1981 as Secretary of the Communist Party and five years later with Raisa as ruler of the Soviet Union. On his first visit the authorities had arranged that he should see the Tower of London but on the day itself he decided instead to stop his motorcade at St Paul’s and he came unannounced to be received by the vergers. He was as inquisitive as he was with world rulers and inquired what the dome was for. The dean’s verger gave a firmly uncompromising reply: “Sir, in order to worship God.”

When he visited St Paul’s more formally years later with Raisa and their daughter, preparations for Christmas were going on in the cathedral. The visitors were fascinated by the crib carved by Astrid Zidower, the Polish artist, who emphasised the struggle needed to get to Bethlehem with its figures outside the stable peering through cracks in its walls.

When Mrs Thatcher visited Russia, arrangements were made for her to light a candle at the monastery at Zagorsk. In the era of perestroika space was found for the spirit even in an officially atheist country.

Converting what Marxism would call “the Christian myth” into reality is giving active love real power in social, economic and political life. In his last address to Soviet citizens as President of the Soviet Union, on December 25, 1991, Gorbachev said: “We live in a new world. An end has been put to the Cold War, the arms race and the insane militarisation of our country which crippled our economy, distorted our thinking and undermined our morals.”

He saw that no one wanted to let go of power and so often used a bloody military short cut to solve political problems that needed a patient thoughtful approach.

Speaking to the students at the Sorbonne in 1989 he had insisted that politics, science and ethics should always be held together or the consequences would be fatal. He was working out, against an Enlightenment background, those childhood intuitions of the coexistence of Marx and the icon lamp. He also visited Pope John Paul II and established relations with the Vatican. Years before he had said to the British Parliament that “Europe is our common home”. He saw the Enlightenment and the Spirit as both part of the human inheritance.

The world needs moments when those with strong but differing convictions can work together for the common good. The World Health Organisation, which spearheads the fight against the Aids pandemic, has staff members with strong religious convictions and with none.

Dr Petra Clarke, who led the London delegates in the General Synod vote to ordain women, worked for women raped in Bulawayo and became a doctor in the Medical Foundation for the Care of Victims of Torture – trying to heal very different victims with different allies.

Amnesty International, Dr Barnado’s and Telephone Samaritans all depend on volunteers with various convictions.

In a talk for Lent Cherie Blair pointed out how those in England concerned with the rule of law and victim/oppressor reconciliation can learn from Zacchaeus (Luke xix, 1-10), who met and repaid his victims.

Those symbols long ago in the Urals, where Gorbachev grew up, which spoke so effectively of “peaceful coexistence”, have never been more needed in our global society.

Alan Webster is Dean Emeritus, St Paul’s Cathedral