For the holy Virgin did not bare mere man but true God: and not mere God but God incarnate, Who did not bring down His body from Heaven, nor simply passed through the Virgin as channel, but received from her flesh of like essence to our own and subsisting in Himself. For if the body had come down from heaven and had not partaken of our nature, what would have been the use of His becoming man? For the purpose of God the Word becoming man was that the very same nature, which had sinned and fallen and become corrupted, should triumph over the deceiving tyrant and so be freed from corruption, just as the divine apostle puts it, For since by man came death, by man came also the resurrection of the dead. If the first is true the second must also be true.
The Apostle says: God sent forth His only-begotten Son, made of a woman. He did not say made by a woman. Wherefore the divine apostle meant that the only-begotten Son of God is the same as He who was made man of the Virgin, and that He who was born of the Virgin is the same as the Son of God.
But He was born after the bodily fashion inasmuch as He became man, and did not take up His abode in a man formed beforehand, as in a prophet, but became Himself in essence and truth man, that is He caused flesh animated with the intelligent and reasonable to subsist in His own subsistence, and Himself became subsistence for it. For this is the meaning of ‘made of a woman.’ For how could the very Word of God Himself have been made under the law, if He did not become man of like essence with ourselves?
Hence it is with justice and truth that we call the holy Mary the Mother of God. For this name embraces the whole mystery of the dispensation of salvation. For if she who bore Him is the Mother of God, assuredly He Who was born of her is God and likewise also man. For how could God, Who was before the ages, have been born of a woman unless He had become man? For the son of man must clearly be man himself. But if He Who was born of a woman is Himself God, manifestly He Who was born of God the Father in accordance with the laws of an essence that is divine and knows no beginning, and He Who was in the last days born of the Virgin in accordance with the laws of an essence that has beginning and is subject to time, that is, an essence which is human, must be one and the same. The name in truth signifies the one subsistence and the two natures and the two generations of our Lord Jesus Christ.
When the fullness of time had come, the messenger of the Lord was sent to her, with the good news of our Lord's conception. And thus she conceived the Son of God by the good pleasure of the Father and co-operation of the Holy Spirit. She ministered to the Creator in that He was created, to the Fashioner in that He was fashioned, and to the Son of God in that He was made flesh and became man from her pure and immaculate flesh and blood, satisfying the debt of the first mother. For just as the latter was formed from Adam without connection, so also did the former bring forth the new Adam.
For He who was of the Father, yet without mother, was born of woman without a father's co-operation. The Son of God incarnate, therefore, was born of her, not a divinely-inspired man but God incarnate; not a prophet anointed with energy but the Anointed One in His completeness, so that the Anointer became man, not by a change of nature but by union in subsistence. For the Anointer and the Anointed were one and the same, anointing in the capacity of God Himself as man. Must there not therefore be a Mother of God who bore God incarnate? Assuredly she who played the part of the Creator's servant and mother is in all strictness and truth, in reality, God's Mother and Lady and Queen over all other created things.
This blessed woman, called blessed by all generations, who was deemed worthy of gifts that are supernatural, suffered those pains which she escaped at Christ’s birth, in the hour of the passion, enduring from motherly sympathy the rending of the bowels, and when she beheld Him, Whom she knew to be God by the manner of His generation, killed as a malefactor, her thoughts pierced her as a sword, and this is the meaning of this verse: Yea, a sword shall pierce through your own soul also. But the joy of the resurrection transforms the pain, proclaiming Him Who died in the flesh, to be God.