Pope Francis urged Iraq’s Christians on Sunday to forgive the injustices committed against them by Muslim extremists and to rebuild as he visited the wrecked shells of churches and met ecstatic crowds in the community’s historic heartland, which was nearly erased by the Islamic State group’s horrific reign.

At each stop in northern Iraq, the remnants of its Christian population turned out, jubilant, ululating, decked out in colorful dress, though heavy security prevented Francis from plunging into the crowd as he would normally do. Nonetheless, they simply seemed overjoyed that he had come and that they had not been forgotten.

It was a sign of the desperation for support among an ancient community uncertain whether it can hold on. The traditionally Christian towns dotting the Nineveh Plains of the north emptied out in 2014 as Christians — as well as many Muslims — fled the Islamic State group’s onslaught. Only a few have returned to their homes since the defeat of IS in Iraq was declared four years ago, and the rest remain scattered elsewhere in Iraq or abroad.

Bells rang out in the town of Qaraqosh as the pope arrived. Speaking to a packed Church of the Immaculate Conception, Francis said “forgiveness” is a key word for Christians.

“The road to a full recovery may still be long, but I ask you, please, not to grow discouraged. What is needed is the ability to forgive, but also the courage not to give up.” The Qaraqosh church has been extensively renovated after being vandalized by IS militants during their takeover of the town, making it a symbol of recovery efforts.

Iraq’s Christian population, which have exited here since the time of Christ, has dwindled from around 1.5 million before the 2003 US-led invasion that plunged the country into chaos to just a few hundred thousand today.

Francis’s visit to Iraq, which was on its last day Sunday, aimed to encourage them to stay and help rebuild the country and restore what he called its “intricately designed carpet” of faith and ethnic groups.

Earlier Sunday, Francis, dressed in white, took to a red carpeted stage in the north’s main city, Mosul, surrounded by the grey hollowed-out shells of four churches nearly destroyed in the war to oust IS fighters from the city.

It was a scene that would have been unimaginable years earlier. Mosul, Iraq’s second largest city, was at the heart of the IS so-called “caliphate” and witnessed the worst of the group’s rule inflicted on Muslims, Christians and others, including beheadings and mass killings.

“How cruel it is that this country, the cradle of civilization, should have been afflicted by so barbarous a blow,” Francis said, “with ancient places of worship destroyed and many thousands of people – Muslims, Christians, Yazidis — who were cruelly annihilated by terrorism and others forcibly displaced or killed.”