Friends, today we celebrate the Blessed Virgin Mary as the Mother of God.
St. Irenaeus says that, throughout the history of salvation, God was trying on humanity, gradually suiting divinity and humanity to one another—preparing for the Incarnation. All of that preparation was a prelude to the Israelite girl who would say yes to the invitation to be the Mother of God.
To say that Mary is the Mother of God is to insist on the density of the claim that God truly became human. As Fulton J. Sheen commented, Mary is like the moon, for her light is always the reflection of a higher light.
Catholic theology has drawn a further implication from Mary’s status as Mother of God—her role as Mother of the Church. If she is the one through whom Christ was born, and if the Church is indeed Christ’s Mystical Body, then she must be, in a very real sense, the Mother of the Church. She is the one through whom Jesus continues to be born in the hearts of those who believe. This is not to confuse her with the Savior, but it is to insist on her mission as mediator and intercessor.