Tens of thousands of Christians persecuted and displaced by Islamic State will on Friday gather to pray together for the Church and for Iraq.

The six-hour event in Erbil, Kurdistan, is expected to attract between 25,000 and 50,000 Christians of all denominations, and will be broadcast across the Middle East by Christian satellite network SAT-7.

It is organised by Life Agape – which coordinates a nationwide prayer network in Iraq – in partnership with the Chaldean Catholic Church and other denominations, and comes at the end of 50 days of prayer and fasting.

Among the Christians who gather to pray will be representatives from the villages and towns recently liberated from ISIS near Mosul. They will share testimonies and receive prayer, and two of the region's best known worship leaders, Revd Zyad Shehada from Jordan and Nizzar Faris from Lebanon, will lead the gathering in song.

Those who attend will stand together in the shape of a cross, and will release balloons with written prayers on them "as a symbol of raising prayer on behalf of the whole nation," said George Makeen, SAT-7 ARABIC's programming director.

Makeen added that though many areas have now been liberated from ISIS, the road ahead will be difficult for those people who have suffered violence and lived in fear for the past two years.

"My prayer is for God's peace and wisdom as they experience such difficult times," he said. "While Iraqis celebrate successes in defeating IS and liberation of their towns, the fear of violence committed by Shia militias (the PMU), the fear of regional conflicts between key players (Turkey, Iran and Saudi Arabia), the conflicts between different religious and ethnic groups (Shia, Sunni, Arabs and Kurds), and the fears people will have as they consider returning to homes they were forced to leave: all of these limit the joy and hope people should be experiencing.

"The country still lacks the sense of true unity and belonging," he said. "I pray that God will give leaders wisdom to help their people to feel that the current developments are the start of a better future."

Life Agape Iraq director Maher Barbary highlighted the suffering of Iraq's Christians, who have been especially targeted by ISIS along with other religious minorities. "More than two years ago the Church had a vicious attack that left it in despair. They saw the broken buildings of the Church and the Christian families displaced inside and outside Iraq," he said.

"But, we and others believe God has a different plan, a plan that can turn this dark picture into a bright picture... The Christians of Iraq from all denominations will gather to celebrate this fact – that God's plan will prevail."