Image credit: Philippine Sowerby
The people who walked in darkness
have seen a great light.
On them the sun has risen.
At Christmas, the Christian celebrates the birth of Jesus Christ, born in a humble stable in Bethlehem, into a poor family. Simple shepherds were the first witnesses to this event. (cf Catechism of the Catholic Church n.525)
This unique and altogether singular event of the Incarnation of the Son of God does not mean that Jesus Christ is part God and part man, nor does it imply that he is the result of a confused mixture of the divine and human. He became truly man while remaining truly God. Jesus Christ is true God and true man. (cf Catechism of the Catholic Church n.464).
This is what is celebrated as we kneel during the profession of faith at the words "... and by the Holy Spirit was incarnate of the Virgin Mary, and became man".