Pope Francis has invited people to open their hearts to the light of Jesus in his first Christmas Eve mass.
He spoke of the fight against the "spirit of darkness" as he urged people to walk in the light.
"If we love God and our brothers and sisters, we walk in the light; but if our heart is closed, if we are dominated by pride, deceit, self-seeking, then darkness falls within us and around us," he said.
The Pope pointed to the image of the shepherds who were told about the birth of Jesus, saying they were "among the last, the outcast".
During the mass at St Peter's Basilica in the Vatican, Pope Francis held a statue of the baby Jesus.
In a short video message posted to Instagram, the Archbishop of Canterbury the Most Reverend Justin Welby said: "Christmas means that through Jesus God shows us unconditionally that he loves us. I pray he gives you a very blessed Christmas."
Thousands of pilgrims are in Bethlehem to celebrate the season and last night the Archbishop of Jerusalem, Fouad Twal, celebrated a midnight mass in which he appealed to Christians to stay in the region despite the longstanding conflict between Israel and Palestine.
He called for a "just and equitable solution", as he said for Christians "the answer lies neither in emigration nor in closing in on ourselves. It consists in staying here."
Palestinian President Mahmoud Abbas was among those present at the service.