For a minority devastated by a series of church bombings that killed dozens of Christians, it was a chance for a rare joyous respite.
Despite fears of another jihadist attack, thousands of Catholics waited for hours on Saturday to enter a heavily guarded stadium in the Egyptian capital to pray with Pope Francis.
It was, said Coptic Catholic engineer Maged Francis, a "historic occasion".
"It's unlikely it will ever happen again," he said.
"Today joy has eclipsed the sadness of the last few weeks."
Outside, armed security personnel stood guard and checked vehicles bringing in the pilgrims, while helicopters flew overhead.
Inside a choir sang "Hallelujah, Hallelujah" as the smiling pontiff entered and circled on a golf cart, waving to the crowds who released yellow and white balloons, the colours of the Vatican flag.
The faithful filled up the stadium's terraces and chairs neatly lined up in front of a main stage sheltered by a large white canopy where the pope led a mass of peace.
Well-wishers waved flags as the pontiff advanced slowly along a red carpet adorned with yellow and white flowers.
The pope -- flanked by bodyguards who scanned the crowd from behind their black sunglasses -- bent down smiling to greet children wearing the gilded headgear of ancient Egypt's pharaohs.
Hymns in Italian, Arabic and French resounded across the playing field, as the pontiff bowed before a portrait of the Holy Family escaping to Egypt, and kissed the altar on the main stage.
"Peace be with you," the spiritual leader of the world's 1.3 billion Catholics said in Arabic as he started his homily.
"True faith... makes us see the other not as an enemy to be overcome, but a brother or sister to be loved, served and helped," he then told the crowds in Italian.
"True faith leads us to protect the rights of others with the same zeal and enthusiasm with which we defend our own," he said in the speech translated into Arabic.
In the audience, Nabil Shukri followed the pontiff's words on a service leaflet in Arabic.
"It's very important that he's here. We are not scared of going to church in Egypt," he said, holding a Vatican flag.
Nagwa Kamal, a maths teacher at a Coptic Catholic school in Cairo, said she was delighted to be in the Argentine pontiff's presence.
"We love him so much. We feel he loves peace," she said.
"We have lived through difficult moments but we have overcome them," she said, apparently referring to Coptic church bombings in December and April claimed by the Islamic State group that killed dozens of worshippers.
"Terrorism will not win. It's peace that counts."
IS has threatened more attacks against Egypt's Christians, who make up around 10 percent of the country's population of 92 million.
Manal George, who had come from a Cairo middle-class neighbourhood with her nephew to attend the mass, said the pope's visit brought much-needed cheer to Egypt's Christians.
"By coming to Egypt, the pope has taken away the sadness to replace it with joy," she said.