Though
she became the most famous woman in the history of the world, Mary was born a
simple Jewish girl from a poor family in the house of David,i some 2,000 years
ago. When she was fourteen or fifteen years old, God chose her to be the mother
of Jesus Christ, God incarnate; this simple teenage girl, then became the
Mother of God.ii She was, as a matter of history, called to the unique task of
bringing the Messiah into the world.

Mary is a sign to us all how God loves to
choose “what is weak in the world to shame the strong” (1 Cor. 1:27).

Mary’s life and identity are really all about
her divine son, Jesus Christ. Her greatness, her holiness, in fact, anything of
eternal value in her at all, comes entirely through her relationship with him.
In Mary’s words, “All generations will call me blessed; for he who is mighty
has done great things for me, and holy is his name” (Luke 1:48-49).

According to the context of Luke 1 (especially
verses 26-38), “great things” refers to Mary having just conceived Jesus in her
womb. Mary’s “blessed” state, then, exists solely because of the divine
Christ-child within her.

When
Mary’s cousin Elizabeth encounters Mary soon after Mary conceived Jesus, in
Luke 1:42-43, she gives us more insight into just who Mary of Nazareth is when
she “exclaim[s&91; with a loud cry… Why is this granted me, that the mother of my
Lord should come to me.”

First, we note the reference to Mary as
“Mother of the Lord,” Jesus Christ. But if we understand its Old Testament
antecedent, this God-inspired declaration becomes even more illuminating.
Elizabeth was referring, almost verbatim, to a text from 2 Samuel 6:9 wherein
David exclaims concerning the Old Testament Ark of the Covenant, “And David was
afraid of the LORD that day; and he said, ‘How can the ark of the LORD come to
me?’”

The Ark of the Covenant, we know, was
especially holy, and called the ark of almighty God because it contained within
it three types or prefigurements of Jesus Christ. According to Hebrews 9:4, it
contained the high priest Aaron’s miraculous staff, a sample of the miraculous
bread from heaven—the manna—and the Ten Commandments, or “Ten Words” (dabar in
Hebrew means “word” or “commandment”).

Mary carried within her our true High Priest
(Heb. 3:1), the true “manna from heaven” (John 6:31-32), and the Word made
flesh (John 1:14). Thus, she is the true Ark of the New Covenant.

Mary is correctly called Mother of God because
Jesus Christ, her son, is God. To deny this essential truth of the faith, as
the Council of Ephesus (431) declared, is to cut oneself off from full
communion with Christ and his Church. In the first of many anathemas or
condemnations of St. Cyril (the famous fifth-century bishop of Alexandria) that
would be accepted by the Council, it decreed:

If anyone does not confess that God is truly
Emmanuel, and that on this account the Holy Virgin is the Mother of God (for
according to the flesh she gave birth to the Word of God become flesh by
birth), let him be anathema.

In its definition the council referred to the
prophecy of Isaiah 7:14, which prophesied over 700 years before the birth of
Christ that the Messiah was to be born of a woman and yet he was to be “God
with us.” Thus, we have evidence from both the Old and New Testaments
testifying to Mary as Mother of God.

The
Catechism of the Catholic Church (CCC) sums up everything for us:

Called
in the Gospels “the mother of Jesus,” Mary is acclaimed by Elizabeth, at the
prompting of the Spirit and even before the birth of her son, as “the mother of
my Lord.” In fact, the One whom she conceived as man by the Holy Spirit, who
truly became her Son according to the flesh, was none other than the Father’s
eternal Son, the second person of the Holy Trinity. Hence the Church confesses
that Mary is truly “Mother of God” (CCC 495). – From 20 Answers: Mary