Pope Francis visited a city reduced to rubble in the fight with the group calling itself Islamic State, which had tortured other faiths' followers while it held control and celebrated Sunday Mass there.
Joyous crowds later welcomed him to Iraq's Christian heartland, The New York Times reported.
"Here in Mosul, the tragic consequences of war and hostility are all too evident," Francis said.
"How cruel it is that this country, the cradle of civilization, should have been afflicted by so barbarous a blow, with ancient places of worship destroyed and many thousands of people -- Muslims, Christians, Yazidis, and others -- forcibly displaced or killed."
Thousands of people were killed during the battle to recapture Mosul from ISIS, which controlled the city between 2014 and 2017, waging its war in Islam's name.
"Our gathering here today shows that terrorism and death never have the last word," Francis said, speaking amid the rubble of an old church that only a few years ago had been used as a prison and shooting range by the extremists of the Islamic State.
"Even amid the ravages of terrorism and war, we can see, with the eyes of faith, the triumph of life over death."
FIRST PAPAL VISIT TO IRAQ
The Mosul visit came on the third day of the Pope's tour of the war-ravaged nation, the first papal visit to Iraq, and Francis' first trip outside Italy since the coronavirus pandemic began. He has repeatedly denounced religious extremism and called for friendship between religions during the trip.
Appearing on a brilliant red carpet against a backdrop of rubble and ruin, Pope Francis visited the once-vibrant Iraqi city of Mosul on Sunday to illustrate the terrible cost of religious fanaticism, showing how, in that ravaged place, the price had been blood.
On his last full day of a visit aimed at promoting harmony among people of different faiths, as well as offering support to a Christian community often persecuted, the Pope's visit to Mosul seemed to dispel any notion that his words had been mere abstractions said the Times.
Francis traveled to the Qaraqosh, the largest Christian city in Iraq, after leaving Mosul. Like Mosul, Qaraqosh was also controlled by the ISIS terrorists for more than two years.
The Pope visited the city's Church of the Immaculate Conception, where he gave a speech and led a prayer.
Thousands of people greeted him there -- a marked difference from his visits to other locations across Iraq. The government has imposed a total curfew for the entirety of the four-day papal visit to minimize health and security risks.
Late on Sunday, the Pope celebrated Mass at the Franso Hariri Stadium in Erbil, Iraq, State-run Iraqiya TV reported.
Some 8,000 people gathered at the stadium to welcome the Pope there, security officials told CNN.
According to officials, the plan had been to have the 35,000 seat-stadium at some 50 percent capacity with an empty seat between each of the attendees to allow for social distancing.
However, images from the stadium showed swathes of the stadium stands filled with people seated closely together without physical distancing.
On the second day of his visit to Iraq, the preceding day, Francis had a private, 45-minute meeting with Grand Ayatollah Ali al-Sistani, 90, a revered spiritual and highly influential leader of Shia Muslims.
"The unprecedented encounter is widely considered of the utmost importance for Christian-Muslim relations and peace in Iraq and other countries," America Magazine, The Jesuit Review reported March 6.
By meeting with Grand al-Sistani in the holy city of Najaf, Francis threaded a political needle, seeking an alliance with an extraordinarily influential Shiite cleric who, unlike his Iranian counterparts, believes that religion should not govern the state.
"By meeting with Grand Ayatollah Ali al-Sistani in the holy city of Najaf, Francis threaded a political needle, seeking an alliance with an extraordinarily influential Shiite cleric who, unlike his Iranian counterparts, believes that religion should not govern the State," said The New York Times.