5 Lo, they are born of God; whereby is it brought to pass that they should be born of God, who were first born of men? Whereby is it brought to pass, whereby? “And the Word was made Flesh, that It might dwell among us.” Wondrous exchange; He made Flesh, they spirit. What is this? What condescension is here, my brethren! Lift up your minds to the hope and comprehension of better things. Give not yourselves up to worldly desires. “You have been bought with a Price;” for your sakes the Word was made Flesh; for your sakes He who was the Son of God, was made the Son of man: that you who were the sons of men, might be made sons of God.
What was He, what was He made? What were ye, what were ye made? He was the Son of God. What was He made? The Son of man. You were the sons of men. What were ye made? The sons of God. He shared with us our evil things, to give us His good things. But even in that He was made the Son of man, He is different much from us. We are the sons of men by the lust of the flesh; He the Son of man by the faith of a virgin. The mother of any other man whatever conceives by a carnal union; and every one is born of human parents, his father and his mother.
But Christ was born of the Holy Ghost, and the Virgin Mary. He came to us, but from Himself departed not far; yea from Himself as God He departed never; but added what He was to our nature. For He came to that which He was not, He did not lose what He was. He was made the Son of man; but did not cease to be the Son of God. Hereby the Mediator, in the middle. What is, “in the middle”? Neither up above, nor down below. How neither up above, nor down below? Not above, since He is Flesh; not below, since He is not a sinner. But yet in so far as He is God, above always. For He did not so come to us, as to leave the Father. From us He went, and did not leave us; to us will He come again, and will not leave Him.
Source: Sermons on Selected Lessons of the New Testament (New Advent)