God decided to incarnate his only son, Jesus Christ, to find a mother, and then live on earth so that people can better understand God, learn to love God, and love each other better. “Christmas” means “celebrate Christ”, celebrating the moment when a young Jewish woman Maria gave birth to Jesus.
When Mary was about to give birth, the Roman government issued an order that all people in Bethlehem must declare their household registration. Joseph and Mary had to obey.
When they arrived in Bethlehem, the sky was faint, and the two of them could not find a hotel to sleep in. There was only one stable for temporary accommodation. At this moment, Jesus is about to be born!
So Mary had to be on the manger and gave birth to Jesus. In order to commemorate the birth of Jesus, later generations set December 25th as Christmas and celebrate Mass every year to commemorate the birth of Jesus.