The apostle Paul, in his letter to the Galatians, clearly states that “God sent his Son, born of a woman” (Gal 4:4). And in his letter to the Romans, he says, “his Son, born of David’s seed according to the flesh, constituted Son of God in power, according to the Spirit of holiness that raised him from the dead, Jesus Christ our Lord” (Rom 1:3-4).
Had it been otherwise, his descent into Mary would have been superfluous. For why would he have descended within her, if he did not need to take something from her? Furthermore, if he had not taken anything from Mary, he would not have been accustomed to eating earthly food . . . nor, after fasting forty days, like Moses and Elijah, would he have felt hunger pangs (cf. Mt 4:2), and if his body had not felt the need for nourishment, neither would his disciple John have written of him: “Jesus, tired from the journey, sat down” (Jn 4:6). Nor would David have foretold of him: “They have added to the sorrow of my wounds” (Ps 69:27). Nor would (Jesus) have wept over Lazarus (cf. Jn 11:35) or sweated drops of blood (cf. Lk 22:44) or said, “My soul is exceedingly sad” (Mt 26:38), nor would blood and water have flowed from his pierced side (cf. Jn 19:34). These are all signs that he took flesh from the earth, recapitulating this flesh in himself to save his own creation.
For this reason, Luke presents a genealogy that runs from the Lord’s birth back to Adam, comprising seventy-two generations (cf. Lk 3:23-38). Thus he joins the end to the beginning and shows (Jesus) is the One who recapitulated in himself all the scattered peoples since the time of Adam and all the languages and human generations, including Adam himself. Hence, Paul called this same Adam “the type of the one who was to come” (Rom 5:14), because the Word, the Craftsman of all things, had already formed, in Adam, the economy concerning the humanity in which the Son of God would clothe himself. At first, God made man animal (= physical), apparently so that he could be saved by the spiritual Man (cf. 1 Cor 15:46). Since the Savior was preexistent, (his creature) who needed salvation had to come into existence also, so that the Savior would not exist to no purpose.
In accordance with this design, the Virgin Mary was found obedient when she said, “Behold your handmaid, O Lord; let it be done to me according to your word” (Lk 1:38). But Eve disobeyed, and she did so while still a virgin.
Even though Eve had Adam for a husband, she was still a virgin. For “they were both naked” in paradise “and were unashamed” (Gen 2:25), since they had been created a short time previously and had no idea about the generation of children; indeed, they first had to become adults, and only then did they begin to multiply. By disobeying, Eve became the cause of death for herself and for the whole human race. In the same way Mary, though she also had a husband, was still a virgin, and by obeying, she became the cause of salvation for herself and for the whole human race.
For this reason, the law calls a woman engaged to a man his wife, even though she is still a virgin; this indicates the parallel (recirculatio) between Mary and Eve. Just as, once something has been bound, it cannot be loosed except by undoing the knot in reverse order, even so the first knots were untied by the (undoing of the) second ones, and, inversely, these last free the first. It works out that the first knot is untied by the second, and the second causes the loosing of the first.
This is the reason why the Lord declared that the first would be last and the last would be first (cf. Mt 19:30). And the prophet affirms the same thing when he says, “Sons shall be born to you in place of your fathers” (Ps 45:16). The Lord, having become “the firstborn of the dead” (cf. Col 1:18) and having received the ancient fathers in his bosom, regenerated them into the life of God, becoming himself the first of the living (cf. Col 1:18), as Adam had become the first of the dying. That is why Luke began his genealogy from the Lord and then worked back to Adam: to show that it was not the fathers who regenerated the Son, but rather the Son who regenerated them into the gospel of life. And so the knot of Eve’s disobedience was untied by Mary’s obedience. What Eve bound through her unbelief, Mary loosed by her faith.
Irenaeus of Lyons, Adversus haereses 3:22. This passage was excerpted from Luigi Gambero, Mary and the Fathers of the Church: The Blessed Virgin Mary in Patristic Thought, Ignatius, 1999.