How did the Catholic Church come to the conclusion that the Blessed Virgin Mary is the Mother of God? There are those of other religions who reject this belief, indicating that there is no biblical evidence to support this dogma. Let us review what the Holy Bible has to say on the subject.
Before it can be stated that Mary is the Mother of God, it is necessary to locate biblical references to the fact that Jesus is truly God. We find such references in The Letter of Paul to the Colossians.
“For in Him (Jesus) all the fullness of God was pleased to dwell.” [Col. 1:19] “For in Him (Jesus) the whole fullness of deity dwells bodily.” [Col. 2:9]
When it is stated that the fullness of God was pleased to dwell in Jesus, it means that in Jesus dwelled the Father, the Son and the Holy Spirit to the fullness. These two biblical passages affirmed that Jesus, while being fully human, was also fully God. In Jesus was present two natures, the Divine nature and the human nature.
In The Second Letter of John, we read:
“Many deceivers have gone out into the world, those who do not confess that Jesus Christ has come in the flesh; any such person is the deceiver and the antichrist.” [2 John 7] To fully understand this passage, it is necessary to understand the following. The name “Jesus” means “Jehovah is salvation” or in simple terms, “God saves.” The name “Christ” means “the anointed.” The full name of “Jesus Christ” means that “the anointed One, Jehovah is salvation.” “Jehovah” is one of the names given to God in the Old Testament. The Second Letter of John states that the anointed One, Jehovah (God) has come in the flesh to save mankind. This is a very powerful statement!
Having said this, The Second Letter of John further states that anyone who rejects the truth that Jesus Christ is the anointed One, Jehovah the Saviour (meaning “God the Saviour”) in the flesh, such a person is a deceiver and the antichrist.
Another biblical passage that affirms the deity (godliness) of Jesus is found in the Gospel of John where it states, “In the beginning was the Word, and the Word was with God, and the Word was God.” [Jn. 1:1]
Having affirmed beyond any doubt the deity of Jesus, we now turn to a biblical passage that clearly states that Mary is the Mother of God. In the Gospel of Luke, we read:
“In those days Mary set out and went with haste to a Judean town in the hill country, where she entered the house of Zechariah and greeted Elizabeth. When Elizabeth heard Mary’s greeting, the child leaped in her womb. And Elizabeth was filled with the Holy Spirit and exclaimed with a loud cry, ‘Blessed are you among women, and blessed is the fruit of your womb. And why has this happened to me, that the mother of my Lord comes to me? For as soon as I heard the sound of your greeting, the child in my womb leaped for joy. And blessed is she who believed that there would be a fulfillment of what was spoken to her by the Lord.’” [Lk. 1:39-45]
When Elizabeth said, “the mother of my Lord,” while filled with the Holy Spirit, she clearly meant that Mary was the mother of God. Through Elizabeth, the Holy Spirit revealed the truth to mankind.
Church Tradition reveals to us that the faithful of the Catholic Church, from the days of its birth, have always believed that Mary was the Mother of God. Because of this belief that existed during the first centuries of the Church, the Ecumenical Council of Ephesus (431 A.D) proclaimed the dogma of Mary, Mother of God. Such a proclamation did not affirm a new doctrine, but rather affirmed what was the common belief of the christians.
On the matter of the dogma of Mary, the Mother of God, the Catechism of the Catholic Church states:
"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' (Theotokos)" [C.C.C. # 495]
Finally, early Church writings affirm that Mary was the Mother of God. I quote the following:
From Irenaeus, "The Virgin Mary, being obedient to his word, received from an angel the glad tidings that she would bear God" (Against Heresies, 5:19:1 [A.D. 189])
From Peter of Alexandira, "They came to the church of the most blessed Mother of God, and ever-virgin Mary, which, as we began to say, he had constructed in the western quarter, in a suburb, for a cemetery of the martyrs" (The Genuine Acts of Peter of Alexandia [A.D. 305])
"We acknowledge the resurrection of the dead, of which Jesus Christ our Lord became the firstling; he bore a body not in appearance but in truth derived from Mary the Mother of God" (Letter to all non-Egyptian Bishops 12 [A.D. 324])
From Ambrose of Milan, "The first thing which kindles ardor in learning is the greatness of the teacher. What is greater than the Mother of God? What more glorious than she whom Glory itself chose?" (The Virgins 2:2 [A.D. 377])