Catholic charity Aid to the Church in Need (ACN) repaired e Great Al-Tahira Church (Church of the Immaculate Conception) in Baghdeda, the largest Christian town in the Nineveh Plains.
Syriac Catholic Archbishop Petros Mouche of Mosul said the restoration of the once fire-damaged church symbolised something great for the local community.
"For us, [the Great Al-Tahira] Church is a symbol. This church was built in 1932, and it was the villagers of Baghdeda who constructed it," he said.
"For this reason, we want this symbol to remain as a Christian symbol to encourage the people, especially the locals of Baghdeda, to stay here.
"This is our country, and this is a witness that we can give for Christ."
The fixing up of the church is one of 14 church repair projects ACN has committed to across the region.
The charity will soon reconstruct the Najem Al-Mashrik Hall and Theatre in Bashiqa, a town occupied by both Christians and Yazidis.
ACN said the project which will enable the venue to once again play host to wedding ceremonies and other celebrations.
Local priest Father Daniel Behnam said: "This project will help ensure the survival of Christian families and provide them with important services.
"In particular, it will help young people, providing a space for pastoral, cultural and youth activities."
ACN's 'Return to the Roots' programme aims to help Christians to return to Nineveh following the defeat of the Islamists.
The charity is also helping to rebuild homes destroyed by ISIS.
Christians in Iraq, who numbered 1.5 million before 2003, have declined by 90 per cent within a generation.
Of the 120,000 Christians who fled the Nineveh Plains following the ISIS invasion in 2014, more than 45,000 have since returned.
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