Prince Charles has made a strong plea for coexistence and understanding between people of different faiths, saying extremism and division are not inevitable.

The prince delivered a reflection on the dire situation for Christian minorities, particularly in the Middle East where many have been forced to flee their homes, during a special service at Westminster Abbey on Tuesday.

He said: “[I have met] many Christians who, with such inspiring faith and courage, are battling oppression and persecution, or who have fled to escape it. Time and again, I have been deeply humbled and profoundly moved by the extraordinary grace and capacity for forgiveness that I have seen in those who have suffered so much.”

Forgiveness, he said, was not passive nor submissive, but “an act of supreme courage, of a refusal to be defined by the sin against you, of determination that love will triumph over hate”.

He paid tribute to those of other faiths who had “shown it is possible to live side by side as neighbours and friends” in the cradle of the three great Abrahamic faiths.

He added: “I know there are Muslim faith leaders who have spoken out in defence of Christian communities and of their contribution to the region. Coexistence and understanding are not just possible, therefore; they are confirmed by hundreds of years of shared experience. Extremism and division are by no means inevitable.”

The service was attended by Justin Welby, the archbishop of Canterbury, and Catholic, Orthodox Christian, Jewish and Muslim leaders. Among those delivering reflections were Sister Nazek Matty from St Catherine of Siena in Iraq, and Theophilos III, the Orthodox Patriarch of Jerusalem.

In his address, Welby said: “To live in a country, or a society where a government, or an armed group, or even a minority of people, consider that you should be consigned to oblivion because of your faith in Christ is an experience without parallel.”

Two days ago, the archbishop warned that Christian communities in the Middle East faced “imminent extinction”. Hundreds of thousands had been forced from their homes and “many have been killed, enslaved and persecuted or forcibly converted”, he wrote in the Sunday Telegraph.

The Christian population of Iraq was less than half what it was in 2003, while Christian “churches, houses and businesses have been damaged or destroyed”, Welby said. “The Syrian Christian population has halved since 2010. As a result, across the region Christian communities that were the foundation of the universal church now face the threat of imminent extinction.”

In his address at the abbey, the prince spoke of a meeting he had earlier this year with a Dominican sister from Nineveh in northern Iraq. In 2014, she had fled along with 100,000 other Christians as Islamic State extremists advanced, leaving behind “the ruins of their homes and churches, and the shattered remnants of their communities”.

She had since returned to Nineveh to rebuild those communities. “Churches, schools, orphanages and businesses are rising from the rubble, and the fabric of that society, which had been so cruelly torn apart, is gradually being repaired,” the prince said. “[It was] the most wonderful testament to the resilience of humanity and the extraordinary power of faith to resist even the most brutal efforts to extinguish it.”

The prince has regularly held meetings at Clarence House in recent years with Christian leaders from the Middle East, as well as priests and ordinary people who have been forced to flee their homes, and has regularly spoken up on their behalf. He has reportedly made private donations to help Christians who have fled to Britain from countries such as Iraq and Syria.

Last March, the prince recorded a special Easter message in support of persecuted Christians and those of other faiths, saying: “I want to assure them that they are not forgotten and that they are in our prayers.”

According to Aid to the Church in Need, which monitors the persecution of Christians, intolerance towards religious minorities is increasing, particularly in parts of Africa, the Middle East and Asia, where militant Islamist movements are growing.

Last week, landmark buildings around the UK were floodlit red to highlight the issue of religious persecution, including a dozen cathedrals and the Houses of Parliament.