Pope Francis has urged the world to let the light of Christmas pierce the "darkness in human hearts" that leads to religious persecution, social injustice, armed conflicts and fear of migrants.
In his "Urbi et Orbi" (to the city and the world) Christmas Day message, the 83-year-old pope called for peace in the Holy Land, Syria, Lebanon, Yemen, Iraq, Venezuela, Ukraine and several African countries caught up in conflicts.
The common thread of his address to tens of thousands of people in St Peter's Square and millions watching or listening around the world was that change starts in the hearts of individuals.
"There is darkness in human hearts, yet the light of Christ is greater still," Pope Francis said, as he marked the seventh Christmas of his pontificate.
"There is darkness in personal, family and social relationships, but the light of Christ is greater. There is darkness in economic, geopolitical and ecological conflicts, yet greater still is the light of Christ," he said.
Pope Francis singled out the persecution of Christians by militant groups in Burkina Faso, Mali, Niger and Nigeria, asking God to console those who suffer for their faith.
The Pontiff, who has been scorned by populist politicians because of his defence of refugees and migrants, dedicated a section of his address to their plight.
"It is injustice that makes them cross deserts and seas that become cemeteries. It is injustice that forces them to endure unspeakable forms of abuse, enslavement of every kind and torture in inhumane detention camps," he said.
This month, Pope Francis called for the closing of migrant detention camps in Libya.
"It is injustice that turns them away from places where they might have hope for a dignified life, but instead find themselves before walls of indifference," he said.
Pope Francis said that while there were many huge problems in the world, people did not have to look far to correct injustices.
They could make a difference in their own communities as a start to healing all the "suffering members of our human family".
"May (God) soften our often stony and self-centred hearts,and make them channels of his love. May he bring his smile, through our poor faces, to all the children of the world: to those who are abandoned and those who suffer violence," he said.
To underscore his message, the two cardinals Francis chose to join him on the basilica's central balcony were Renato Martino, president emeritus of the Vatican's immigration office, and Konrad Krajewski, the papal almoner who distributes aid to Rome's poor and homeless.
"Through our frail hands, may he clothe those who have nothing to wear, give bread to the hungry and heal the sick," he said, adding that through friendship, everyone could be close to the elderly, the lonely, migrants and marginalized people.
"On this joyful Christmas Day, may he bring his tenderness to all and brighten the darkness of this world," he said.