Speaking with Aid to the Church in Need (ACN) as part of its Break the Silence podcast series, Archbishop John Wilson of Southwark said that "it is a sadness that the persecution of Christians around the world is a subject that rarely gets the attention it needs".
Archbishop Wilson added: "I think it is the business of every Christian to look to the support and the defence of a brother or sister - a Christian whatever their circumstances - but especially in the context when they are suffering for their faith…
"As followers of Christ and members of the Church, we have a duty to each other."
He said the "need to speak out and defend our persecuted brothers and sisters is not just a matter of justice - it is about standing in spiritual and practical solidarity with our fellow disciples in the suffering Church as members of the one body of Christ."
During the podcast, in which he spoke with John Pontifex, ACN (UK)'s Head of Press and Public Affairs, the archbishop said that on his visit to Nigeria in July he "was moved by the people" he met and continues "to be moved by people who, regardless of their circumstances, remain faithful".
He added: "Sometimes people who face the greatest hardship have the most impressive and beautiful faith… There is something about the power of the Cross and the Resurrection that they are in touch with in a way that those of us who are not challenged in that way are not."
Archbishop Wilson highlighted that, since the beginning "of Christianity, the story is one of persecution, and it has tragically peppered the history of the Church for as long as there have been followers of Christ. Despite that persecution, despite those martyrdoms the Church flourishes because Christ is alive…
"Christ cannot be martyred - he is risen and therefore we are people of intrinsic, indefatigable and inextinguishable hope."
Speaking about ethnic diversity in his archdiocese, he said he was "proud that we are so richly international" and "that we are genuinely Catholic" - "a kind of all-embracing kaleidoscope of God's creation".
He explained that many of the faithful in Southwark Archdiocese "come from countries where there is persecution and some of them have friends and family who face enormous challenges".
He added that Christians in the UK can learn a lot from people persecuted for their faith - and it is important "never to take for granted the freedoms we have" and to "protect them".
Archbishop Wilson concluded: "ACN's advocacy work is so important… We must unite spiritually in solidarity to defend religious freedom as a fundamental expression of human dignity, which is at the heart of the Church's teaching."