It must be insisted at the outset that Orthodox Christians do not believe that the divinity has its origin in Blessed Mary, or in any human. God the Father is the source and origin of the Godhead, without beginning and entirely outside of time and space. In eternity the Father begets the Son and Word of God, and in eternity the Holy Spirit proceeds from the Father. We use these words because it is beyond human understanding and language to express the relations between the three Divine Persons in the Holy Trinity. But Orthodox are sure of this, the Holy Trinity, our God, has no beginning at all, and cannot be said to have any beginning in the womb of Blessed Mary.
When we use this phrase, Mother of God, we absolutely and completely reject any sense of saying that God finds his origin in Blessed Mary. How could it be so?
But this phrase remains there in the Scriptures, Mother of My Lord, of My God!
How are we to understand the Scriptures?
It is in this manner. We are not to imagine that what the Blessed Mary bore in her womb was the divine nature, as if it could be conceived and have a beginning. That which was conceived in her womb by the Holy Spirit was completely and perfectly human, of the same nature as us without sin. But when was ask WHO it was who was conceived in her of the Holy Spirit we have no answer other than that it was the Son and Word of God. But this is what we have already heard from the angel who visited Blessed Mary. Do we remember that he said…
Luke 1:35 The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God.
Who is it that is born of Blessed Mary? If we believe the Scriptures then we must surely say that it is the Son of God. If it is not the Son of God then we have not been saved at all because only an ordinary man died on the cross, perhaps a prophet, but certainly no-one with the power to save others.
Therefore we must say that Blessed Mary has borne the Son of God in her womb, not according to his divinity, but certainly according to his humanity. And in that humanity he remains always the Son of God. Who did she nurse, who did she care for as he grew into infancy and then into his youth? It was the same Son of God, who is truly and absolutely God the Word?
She was his Mother. He was born of her and took his flesh from her. There is no other name for the relationship. To deny that Blessed Mary is the Mother of God is to deny that Jesus Christ is God. Who will do that when the Scriptures themselves teach us that he is the Son of God and that Blessed Mary is his Mother.
Of course the hesitancy we find in speaking in such a manner is often deep seated and is more to do with an opposition to the perceived failings of Roman Catholicism than to any carefully considered objection to this term. But the Scriptures require us to use this phrase since it preserves that necessary belief we have as Christians that Jesus is the Son and Word of God made flesh, just as the Angel announced to Blessed Mary, and as Elizabeth greeted her.
If Jesus is not the Son and Word of God then Christianity is false, and if he is the Son and Word of God then Blessed Mary is indeed the Mother of God.