He entered into time and humanity through Mary, and became our Savior.
When the shepherds received word of what happened, they came to behold the Child, and then spread the Good News.
The text in the Gospel according to St. Luke says that Mary pondered all these great things that had happened. It must have been amazing for Mary to look at her Baby and marvel that she was holding God.
We, too, are invited to behold this great mystery of the Incarnation, and let God be born in us and in our world.