Family in faith: (from far left) Johan, Anna-Lisa, Nicholas, Ben (husband of Anna-Lisa), Angela, and the four sons of her first marriage, Simon, Mark, Andrew and Jonny

Benedict XVI and Rowan Williams, Pope Francis and Justin Welby – leaders of the Catholic Church and of Anglicanism, have frequently been pictured together, their handshakes symbolic of the accord between the two denominations. At the local level, parishes often work together and many couples live out ecumenism in their own lives in inter-Church marriages.

But few families express the spirit of ecumenism more than the extended Bergström-Allen/Elvin clan. It includes a former Salvation Army member-turned-Catholic, a pair of twin brothers, both former Catholics, of whom one is now an Anglican vicar while the other is a United Reformed Church minister, and two Catholic lay Carmelites.

We have travelled a long way since the 1960s, when Catholic–Anglican dialogue made huge strides forward following the Second Vatican Council. The twins, John and Mark Elvin, were one year old when the famous encounter took place in Rome in 1966 between Pope Paul VI and the then Archbishop of Canterbury, Michael Ramsey. In a dramatic gesture, the pope removed his ring and placed it on the archbishop’s finger as a sign of the bond between them.

It took time for leaps in theological thinking at the highest levels to filter down, however. In their youth, when the twins were raised by their Catholic parents and sent to Catholic schools, they understood that Catholicism was the only denomination that really mattered. “What was clear to me then was that to be a Catholic was the way to heaven,” says John.

Even when their half-brother, Johan Bergström-Allen, who was born in 1979, was growing up, and when the Anglican-Roman Catholic International Commission had been in existence for over a decade, there was still a sense among ordinary parishioners that Catholicism was the “one true Church”. “I used to think that Christian unity meant everyone coming round to the Catholic Church’s way of thinking,” Johan says. “I now realise there’s diverse thinking within my own denomination, and that unity does not mean conformity. Celebrating diversity is now my goal.”

Johan’s family began as a traditionally Catholic one. He and the twins’ mother, Angela, were brought up in a devout Catholic family with strong recusant Lancashire links. She and her first husband, David Elvin, had four sons, all educated in Marist schools in Kent. It was here that she first encountered the Carmelites at Aylesford Priory, when her father volunteered to help rebuild it. Today, Angela is a professed member of the Carmelite Third Order. “When I first married in the early 1960s, there was little talk of ecumenism,” she says. “My parents were from Catholic families and we all had a Catholic education. There was never any doubt that my children would be brought up as Catholics and would attend Catholic schools.”

Angela’s second husband, Nicholas Bergström-Allen, was born in Sweden. His parents were senior officers in the Salvation Army, and he had been encouraged to learn to play an instrument in order to take part in Army services. Music drew him to Catholic liturgy and he was received into the Church in the 1970s, while also serving as an organist in both the Church of England and the Church of Sweden. As a musician, he was keen that his and Angela’s son, Johan, should have a musical education, and so Johan became a chorister and boarder at St John’s College, Cambridge. It was the young man’s first glimpse of a different musical tradition, and he grew to love Anglican church music.

In the 1980s, and even into the 1990s, there was still a sense of otherness about people of different denominations. “I remember being told by other boys that they were Christian, whereas I was Catholic,” Johan recalled. Then, a Catholic priest suggested that as he spent so much time at Anglican services as a chorister, Johan could receive Communion with the others.

Meanwhile, his older twin brothers, Mark and John, were coming into contact with other Christians through higher education (two other brothers, Andrew and Simon, have remained not so deeply engagaged with the Catholic Church and experienced other Christian denominations). Mark eventually became a member of the United Reformed Church, and is now the minister at Bowthorpe church, near Norwich, which is sponsored in an ecumenical partnership by the Anglicans, Baptists and Methodists, as well as the United Reformed Church.

Mark’s church also hosts a Catholic Charismatic Day of Renewal twice a year, a Syrian Orthodox Church liturgy once a month and a meeting of the Friends – the Quakers – every fifth Sunday evening. “Ecumenism is now more collaboration than visible unity,” he says. “Many speak about unity in diversity, which is a helpful phrase because we are not all the same but we all belong to Christ. Most people do not understand our denominations and wonder why we aren’t all one Church. I say we are one Church – but we have different outlets! Unity in diversity.”

On the other side of the country, Mark’s brother, John, had started attending an Anglican church in Plymouth – at first, he admits, to meet girls. But, he says: “I quickly realised that my confidence had been ill-founded – that the way to heaven wasn’t by being ‘a good Catholic’, but about trusting in Jesus for salvation, putting my confidence in the Cross, not in myself or my denomination,”

Always feeling that he would like to marry one day, John had ruled out ordination in the Catholic Church, but found himself drawn to the idea of priesthood in the Church of England. He and Mark remain grateful for the Christian foundation that being Catholic gave them, and see themselves not so much as having converted from Catholicism, but as having undergone a more profound conversion to living for Christ.

As to ecumenism today, John (now known as Jonny) believes that greater unity is unlikely to happen at the highest levels but that moving closer is possible at the local level. As vicar of Trinity Church, Exeter, he welcomes everyone to take Communion: “I know the Church has rules about baptism and confirmation and I understand the reasons, but I’m more concerned with the gospel invitation held out by Jesus to all who would come to him.”

Johan, too, has had issues about sharing Communion – one of the most difficult issues for Catholics who yearn for greater unity with other Christians. In the late 1990s, as a student at York University, he attended an ecumenical service for Ash Wednesday with Anglicans, Catholics and Methodists. Members of the different denominations went to different rooms for Eucharistic prayers and Communion before joining together again for a sign of peace. “I am not diminishing the differences between us,” he says, “but it was shocking to experience the reality of the divides.”

Since then, Johan has found his own place in Christianity. As a gay man, he wondered if he would be welcomed anywhere but he decided to stay in the Catholic Church, and became a member of the Carmelite Third Order Secular. Having family members in different denominations highlights the Churches’ strengths, he says: the wide range of worship styles in the United Reformed Church, its enthusiasm, especially among its women ministers, for justice and peace issues; the Church of England’s ability to be a broad church and the official voice it gives to the laity; the Catholic Church’s deep roots in tradition and its powerful spirituality. Like his mother and his sister, Anna-Lisa, he is also a regular Lourdes volunteer.

Spread across the country, the family rarely gets together. Nor do they spend much time discussing religion. But Angela Bergström-Allen looks on their disparate faith journeys with satisfaction. “I am immensely proud of all my children, who serve their fellow men and women in diverse ways,” she says.

One occasion when they did all meet was for Jonny’s ordination in Rochester Cathedral. They felt it was right to receive Communion as a family in support of his ministry. Although the Catholic Church does allow the reception of Communion in another Church in exceptional circumstances, there are some Catholics who may disapprove. But, as Angela put it: “In my kind of Catholicism, rules can sometimes be broken. Love is stronger.”

Mark recalls that he once wrote on the inside cover of his Bible: “Unity is something to be discovered, not created.” The lesson is clear. “In Christ we are already united,” he says. “Unity isn’t something we create but something we discover – that we are already one in Christ. It is this discovery that changes attitudes.”

Catherine Pepinster is a former editor of The Tablet and the author of The Keys and the Kingdom: The British and the Papacy from John Paul II to Francis, which is published by Bloomsbury.