Why do we celebrate the solemnity of Mary, the Mother of God?
Having just celebrated the Nativity the Church concludes the octave of Christmas by honoring Mary under her greatest title, the Mother of God. Upon the fact of her divine Motherhood depends all her dignities and prerogatives.
The Catechism of the Catholic Church (paragraph 509) teaches, “Mary is truly ‘Mother of God’ since she is the mother of the eternal Son of God made man, who is God himself.”
The solemnity of Mary, Mother of God, is a holy day of obligation, and we celebrate this feast every year on January 1 in honor of her.