Pope Francis urged Christians to celebrate the birth of Jesus by thinking about the plight of today's children, bemoaning how some must escape bombs or flee in migrant boats and how others are prevented from being born at all.
Francis celebrated a somber Christmas Eve Mass in a packed St. Peter's Basilica, processing to the altar behind cardinals draped in golden vestments as the Sistine Chapel choir sang "Gloria" and the church bells rang out across Rome.
Francis has spent much of the year denouncing the Islamic extremist violence that has driven Christians from Mideast communities that date to the time of Christ. He has also demanded Europe in particular do more to welcome refugees, saying Jesus himself was a migrant who deserved more than being born in a manger.
In his homily, Francis urged people to reflect on how children today aren't always allowed to lie peacefully in a cot, but rather "suffer the squalid mangers that devour dignity."
Like the shepherds of Bethlehem, may we too, with eyes full of amazement and wonder, gaze upon the Child Jesus, the Son of God.— Pope Francis (@Pontifex) December 24, 2016
Pope Francis has also been active on Twitter in the run up to Christmas.
Among the indignities, he said, are "hiding underground to escape bombardment, on the pavements of a large city, at the bottom of a boat overladen with immigrants."
"Let us allow ourselves to be challenged by the children who are not allowed to be born, by those who cry because no one satiates their hunger, by those who do have not toys in their hands, but rather weapons," he added.
The Mass late Saturday was the first major event of the Christmas season, followed by Francis' noon Urbi et Orbi (To the city and the world) blessing on Christmas Day.
In another appeal, Francis called for the faithful to not get caught up in the commercialization of Christmas "when we are concerned for gifts but cold toward those who are marginalized."
Materialism has "taken us hostage this Christmas," he said. "We have to free ourselves of it!"
Pope Francis has a lot of fans on social media.
(The Associated Press contributed to this report)