In the traditional Catholic calendar, October 11 is the Feast of the Divine Maternity of the Blessed Virgin Mary. This feast day was transferred to January 1 in the post-Vatican II liturgy and renamed the Solemnity of Mary Mother of God. The Divine Maternity is one of the four great Marian dogmas to have been infallibly proclaimed by the Catholic Church. These are the infallibly defined dogmas as they pertain to Our Lady:
Mary the Mother of God (the Divine Maternity);
Mary conceived without Original Sin (the Immaculate Conception);
Mary a Virgin before, during, and after the birth of Christ (the Perpetual Virginity); and
Mary assumed body and soul into Heaven (the Assumption).
It is well believed by Catholic theologians and saints that a fifth and final Marian dogma will be infallibly declared by the Church before the Second Coming of Christ:
Mary as Co-Redemptrix and Mediatrix of All Graces.
Pope Francis has already stated that he is not about to proclaim this as a fifth Marian dogma, and so we will have to wait for a future pontificate for the final Marian dogma to be declared ex cathedra (that is, infallibly, from the Seat of Peter).
The Divine Maternity is, in a certain sense, the foundation and bedrock of all the graces and privileges which Our Lady received from God, for the simple reason that all the other graces either flow from, or are ordered to, the reality of Mary being destined to conceive and give birth to the Incarnate Word.
One of my favourite Marian titles is "Our Lady of the Blessed Sacrament." In Latin, it sometimes goes by the title Mater Eucharistiae, which means "Mother of the Eucharist." This title is so beautiful because it points to the role that the Virgin Mary plays in giving birth not only to the physical, incarnate Son of God, but also, through that physical birth, to the Holy Eucharist itself. There would be no Blessed Sacrament without the Sacred Humanity of Jesus Christ, and He would not have come into this world in the flesh had Our Lady not given her FIAT to the Archangel Gabriel.
The Blessed Virgin is, in a very real sense, therefore, the Mother of the Eucharist. She is the one who engendered the Eucharistic Body of Our Lord. Whenever I offer Holy Mass, and right before the words of Consecration that I say as I bow over the Altar, I am mindful that I, a priest, am doing (in a certain sense) what Our Lady did at Nazareth and in Bethlehem. I am "conceiving" and "giving birth to" the Incarnate Word, the Son of God in human flesh and blood, upon the sacred Altar. When I raise the Body of Christ high above the Altar after the Consecration, I am mindful of the fact that I am holding in my priestly hands the very same Body that Our Blessed Lady carried in her womb, held in her arms, and presented to the world as the Saviour of mankind.
The Church has always seen, in her theology and her traditional liturgical texts, a very profound link between what happened in Bethlehem and what happens around the world in our Catholic Churches every day. The Word became flesh and dwelt amongst us (from Chapter 1 of St. John's Gospel) are words that do not just apply to the birth of Jesus in the manger some two millenia ago; they apply just as well to the Son of God becoming present on our Altars at every single Mass. The manger and the Altar both contain the same mystery: the enfleshment of God, God becoming man. The difference is that the Altar makes present this mystery in a hidden, sacramental way, and that the Altar points as well to the Sacrifice of Calvary.
At the Annunciation, the Word became flesh through the words of the Mother of God to the Archangel: Fiat mihi secundum verbum tuum (Let it be done to me according to thy word). At Holy Mass, the Word becomes flesh through the words of Consecration that the priest utters in persona Christi (in the person of Christ) at the Altar: Hoc est enim Corpus meum (For this is my Body). In the traditional Catholic Mass, these words are uttered silently by the priest, conveying that the One who is the Word can best be encountered in silence.
So the next time that you are present at Holy Mass, I invite you to reflect on what exactly is happening at the Consecration upon that sacred Altar. God is descending from Heaven and becoming man, just like He descended from Heaven and was made incarnate when the Mother of God said her YES to God.
Have a blessed feast of the Divine Maternity!