The crowd is young and there's a World Youth Day atmosphere in sections. Indeed there was a 2002 World Youth Day backpack from Toronto among the growing flock.
Among the older, generation 64-year-old grandfather and businessman Zuhair Espaniola from Nazareth was not going to let this opportunity pass.
Espaniola remembers Pope Paul VI's visit in 1964, when he was 14 years old. Since then he's been present to greet Pope John Paul II and Pope Benedict XVI. The difference this time is that the pope won't go to Nazareth, so Espaniola came here.
The Israeli Arab is particularly excited about this pope.
"This one is our religion," he said in his third language. "The most important thing is that we love, love, love and forgive."
Espaniola is most impressed that Pope Francis will have lunch in Bethlehem with poor families from the refugee camps in the region.
"He doesn't look for the very rich people," he said.
Espaniola fully expects the pope to address peace and the situation of Palestinians.
Israel will have to give up land to get peace, he said.
Security is tight on the square with police, and paramilitaries in fatigues sprinkled through the crowd and ringing the square on rooftops. There were 9,000 tickets distributed for the Mass. Large blocks of pilgrims are in the crowd from the Philippines and Sri Lanka. One very large Polish flag is being carried around the perimeter.
This is the second day and the second Mass of the pope's trip to meet with Ecumenical Patriarch Bartholomew and sign a document pledging friendship between Catholics and Orthodox.
Yesterday Pope Francis celebrated Mass in a stadium in Amman, Jordan, while Patriarch Bartholomew visited Bethlehem.
Bartholomew's visit to the Church of the Nativity included a special message to young Palestinians.
"You, the youth of Bethlehem, are the hope and the future of your homeland," said the Patriarch. "Remain faithful to your historical mission and preserve unextinguished the flame of our Orthodox faith in this land, where the Lord initiated His work of salvation for the whole world. Your presence here as Orthodox Christians is of immense importance. Continue your work with the same passion. May God be with you!"