Not knowing, therefore, what he was bound to think concerning the incarnation of the Word of God, and not wishing to gain the light of knowledge by researches through the length and breadth of the Holy Scriptures, he might at least have listened attentively to that general and uniform confession, whereby the whole body of the faithful confess that they believe in God the Father Almighty, and in Jesus Christ, His only Son , our Lord, who was born of the Holy Spirit and the Virgin Mary. By which three statements the devices of almost all heretics are overthrown. For not only is God believed to be both Almighty and the Father, but the Son is shown to be co-eternal with Him, differing in nothing from the Father because He is God from God , Almighty from Almighty, and being born from the Eternal one is co-eternal with Him; not later in point of time, not lower in power, not unlike in glory, not divided in essence: but at the same time the only begotten of the eternal Father was born eternal of the Holy Spirit and the Virgin Mary. And this nativity which took place in time took nothing from, and added nothing to that divine and eternal birth, but expended itself wholly on the restoration of man who had been deceived : in order that he might both vanquish death and overthrow by his strength , the Devil who possessed the power of death. For we should not now be able to overcome the author of sin and death unless He took our nature on Him and made it His own, whom neither sin could pollute nor death retain. Doubtless then, He was conceived of the Holy Spirit within the womb of His Virgin Mother, who brought Him forth without the loss of her virginity, even as she conceived Him without its loss.
But if he could not draw a rightful understanding (of the matter) from this pure source of the Christian belief, because he had darkened the brightness of the clear truth by a veil of blindness peculiar to himself, he might have submitted himself to the teaching of the Gospels. And when Matthew speaks of the Book of the Generation of Jesus Christ, the Son of David, the Son of Abraham Matthew 1:1, he might have also sought out the instruction afforded by the statements of the Apostles. And reading in the Epistle to the Romans, Paul, a servant of Jesus Christ, called an Apostle, separated unto the Gospel of God, which He had promised before by His prophets in the Holy Scripture concerning His son, who was made unto Him of the seed of David after the flesh Romans 1:1-3, he might have bestowed a loyal carefulness upon the pages of the prophets. And finding the promise of God who says to Abraham, In your seed shall all nations be blessed Genesis 12:3, to avoid all doubt as to the reference of this seed, he might have followed the Apostle when He says, To Abraham were the promises made and to his seed. He says not and to seeds, as if in many, but as it in one, and to your seed which is Christ Galatians 3:16 . Isaiah’s prophecy also he might have grasped by a closer attention to what he says, Behold, a virgin shall conceive and bear a Son and they shall call His name Immanuel, which is interpreted God with us. And the same prophet’s words he might have read faithfully. A child is born to us, a Son is given to us, whose power is upon His shoulder, and they shall call His name the Angel of the Great Counsel, Wonderful, Counsellor, the Mighty God, the Prince of Peace, the Father of the age to come. And then he would not speak so erroneously as to say that the Word became flesh in such a way that Christ, born of the Virgin’s womb, had the form of man, but had not the reality of His mother’s body. Or is it possible that he thought our Lord Jesus Christ was not of our nature for this reason, that the angel, who was sent to the blessed Mary ever Virgin, says, The Holy Ghost shall come upon you and the power of the Most High shall overshadow you: and therefore that Holy Thing also that shall be born of you shall be called the Son of God Luke 1:35, on the supposition that as the conception of the Virgin was a Divine act, the flesh of the conceived did not partake of the conceiver’s nature? But that birth so uniquely wondrous and so wondrously unique, is not to be understood in such wise that the properties of His kind were removed through the novelty of His creation. For though the Holy Spirit imparted fertility to the Virgin, yet a real body was received from her body; and, Wisdom building her a house Proverbs 9:1, the Word became flesh and dwelt in us , that is, in that flesh which he took from man and which he quickened with the breath of a higher life.
–Letter 28.II
Saint Leo the Great
Pope and doctor of the Church. He was called "Great" for feeding his flock with exquisite and prudent preaching and for upholding the orthodox doctrine of the incarnation of God, courageously affirmed by the legates of the Ecumenical Council of Calcedonia. pic.twitter.com/DtrdDzXqCc— Padre Mlassani imc (@Imc_mkwe) November 10, 2020