Today we celebrate the fact that Mary was and is truly the Mother of God. The idea is that Jesus is one divine person, the Son of God, who has a divine nature from all eternity, and who took on an immortal human nature at one specific point in time, 2000 odd years ago. In His divine nature, the Son of God would not have a mother, no; but if He were to be fully human, as He must have a real mother. And so He did. Mary was and is not only an element in the Incarnation of Jesus, but is a mother as truly as any other mother, not only by conceiving and bearing Jesus, but also by nurturing and raising Him in His human nature. And, because Jesus's human nature cannot be separated from His divine person, Mary must truly be also mother to the Second Divine Person, the Son of God. Thus, she is truly the Mother of God.

That is the doctrine, defined infallibly by the Council of Ephesus in 431. Why was this doctrine so important that it became the source of a great flourishing of Marian devotion, including the building of the first church dedicated to Mary, and continues to this day to be a great feast of the Church, coming so soon after Christmas? Let me propose three reasons.

First, the fact that Mary is the Mother of God emphasizes the truth about Jesus Christ. The human Jesus was not merely an exalted human, although He was and is that. The divine Son of God and the human Jesus were truly and fully the same person, so that to this Godhead in the Son can be attributed all things attributed to His humanity, His mother, His life, His actions on earth, His death for our sake, and His rising from the dead, the first promise of our resurrection. And in so taking on humanity in all its fullness, the divine Son of God raised humanity to union with God. As St. Ireneus said, "The Son of God became man, so that the sons of men may become the adopted sons of God."

Second, and on a related point, by making Mary the mother of God, Jesus raised the dignity of motherhood. All fatherhood, whether that of a family or that of a priest, receives its highest dignity by participating in the Fatherhood of God, Father of the Son, and Father of His people on earth, guiding, providing for, and protecting them. Priests received their participation in the divine plan both by participating in this fatherhood and by being, on behalf of Christ, mystically espoused to His bride the Church. Religious women likewise are mystically espoused to Christ on behalf of the Church. Consecrated single people participate most fully in the Trinity by living a life of holy freedom, in the full liberty of the Holy Spirit, as St. Paul did. Martyrs participate in Jesus' sacrifice and in the Eucharist that makes it present by saying like Jesus, "This is my body, this is my blood, given up for you." Where, then does motherhood fit in? Motherhood participates in Mary's motherhood of God by being drawn toward her, who with Jesus had the best of human loves, what Fulton Sheen called "the world's first love." It was the love that the devil raged in vain against, the love that conquered death itself such that Mary reigns with Jesus in heaven, the love that was the height and first promise of the new creation.

Although it is not our immediate subject, one may ask what love did Joseph as foster father represent? Certainly because he fulfilled the roles of a father, protecting, guiding, and providing for his family, he is certainly the model for all fathers, although he could not be the biological father of Jesus, for God Himself would beget Jesus. But Joseph also, by his adoptive fatherhood, brings into its fullest participation in the plan of salvation adoptive parenthood, parenthood that, like St. Joseph guides and defends God's innocent and His children in a fallen world.

Third, because as St. Paul says, the Church is the body of Christ, Mary's motherhood of Jesus makes her the mother of the Church. If we say, as we should, that the Church is the family of God, with God as our Father and all of the faithful adoptive brothers and sisters in Jesus Christ, then one must conclude that there is a mother. After all, what family is complete without a mother? And mother there is in the mother of Jesus and therefore of His body the Church. We can turn to Mary as our mother in heaven, forever interceding for us, with a passionate and undying love that knows no boundaries and no end. When John the beloved disciple was there with Mary at the foot of the Cross, Jesus turned to him and said "Behold thy mother." And to Mary He said, "Behold thy son." John stood there at the Cross on behalf of all struggling and sinful, but still faithful people until the end of time. And, we if we are faithful to the Church, if we take Mary as our model and intercessor, can look forward to the time when we appear before the throne of heaven and Mary says to God and to her Son, "Behold my daughter, behold my son."