Father Iyad Twai is the Roman Catholic parish priest of the village of Beit Sahour, a mile or so away from Beit Lechem – or Bethlehem, as it is better known – in the Palestinian West Bank. Last month, we met for a coffee and a smoke at Bethlehem University and chatted about our respective parishes. It’s a golden rule that, when two clergy get together to talk, they start comparing numbers. He has about 350 families in his parish – about 1,200 people – as well as involvement from the Orthodox and Arab Maronite communities. And his was the village where the shepherds of the gospel of Luke first proclaimed the good news of Jesus’s birth. This is where Christianity began. Some of his parishioners are descendants of those first shepherds, he said. I raised a sceptical eyebrow. Nonetheless, in the game of ecclesiastical top trumps, he had blown me away on all counts.

But, for all of this, Father Iyad is fighting an uphill battle. His community is shrinking, with many younger Palestinian Christians leaving Beit Sahour to find jobs elsewhere in the world. The Israeli occupation has left them with little prospects in their home town. Soon, he says, there won’t be any Christians left. People will come here on air-conditioned coaches to look at buildings like the Church of the Nativity in Bethlehem, but what he calls the “living stones”, ie the local Christian community itself (a reference to 1 Peter, chapter 2), are ignored, as if they don’t exist.

Ani, the ancient capital of the Armenian empire, Turkey, now in ruins (August 2013). Photograph: Linda Dorigo

This book from photographer Linda Dorigo and journalist Andrea Milluzzi, Italians working in the Middle East, give faces to these living stones, away from touristic locations. Their new book – poignantly titled Rifugio (“refuge” or “shelter”) – is a visual record of those who have, through poverty or defiance, refused to become a part of the Christian diaspora and now struggle to live out their faith in an increasingly inhospitable land. “During New Year’s evening Mass in 2011, an explosion destroyed the Saints Church in Alexandria [in Egypt]. Twenty-one Christians died. The story appeared in western newspapers and on television, but, after a few days, the media’s attention faded. We felt the need to know more. So we left to discover stories, families and villages in their everyday lives. We were looking for the heirs of the evangelists and the first pilgrims,” they explain.

When the US launched its invasion of Iraq in 2003, there were 1.5 million Christians living in the country. Saddam Hussein’s foreign minister, Tariq Aziz, was a Christian – demonstrating the relative religious tolerance under that regime. But, by igniting sectarian violence between Sunnis and Shias, the US invasion was a disaster for indigenous Christians, who Muslims associated with the hated crusaders. Now Christians are being slaughtered by Islamic State. Between 2003 and now, three quarters of Iraq’s Christians have been driven from their homes or killed. It’s a story that has repeated itself throughout the Middle East, although, to be fair, it long pre-dates the US invasion. When, a century ago, the Ottomans drove Armenian Christians from Turkey into the Syrian desert to die of starvation, there was a 13% Christian presence in Turkey. Now, they have been all but wiped out. In Egypt, some 600,000 Christians have left during the past 30 years.

A funeral in Deir Abu Hennis, Egypt, where many of the inhabitants have never left the village (July 2012). Photograph: Linda Dorigo

Father Iyad is right to be worried. And Dorigo and Milluzzi have done important work showing us their faces and giving us an emotional connection to their struggle for survival. Many of these communities have existed since the first century. Some of them still pray in Aramaic, the language that Jesus himself prayed in. Now they are approaching extinction. Christianity is being driven from the place of its birth.

Rifugio: Christians of the Middle East by Linda Dorigo and Andrea Milluzzi (Schilt Publishing, £29.95, Amsterdam). Hardbound with dust jacket, 19 x 24.5 cm (portrait), 180 pages with 73 images.

The book is available to buy online now, and in stores from next week (distributed by Thames & Hudson)