Adam blew it. Christ renewed it. Recapitulation.
Recapitulation as atonement is a very biblical idea. Paul speaks of it expressly as the plan and purpose of God. It is the saving work of Christ, through the Incarnation and the Cross:
God did this when he revealed to us the mystery of his will, according
to his good pleasure that he set forth in Christ, toward the administration of the fullness of the times, to head up all things in Christ – the things in heaven and the things on earth. (Ephesians 1:9-10 NET)
The Greek word for “to head up” is anakephalaioo, meaning to gather up into one, to sum up — quite literally, it means to head up. It is recapitulation, or as we would say in today’s jargon, “recap.” Paul tells us that all in heaven and on earth are summed up, headed up, “recapped” and brought to unity, to oneness, in Christ. St. Irenaeus of Lyon (AD 130-202), picking up on Paul, here and elsewhere, speaks specifically of recapitulation as the saving work of Christ:
Wherefore also He passed through every stage of life, restoring to all communion with God ... For it behoved Him who was to destroy sin, and redeem man under the power of death, that He should Himself be made that very same thing which he was, that is, man; who had been drawn by sin into bondage, but was held by death, so that sin should be destroyed by man, and man should go forth from death. For as by the disobedience of the one man who was originally moulded from virgin soil, the many were made sinners, and forfeited life; so was it necessary that, by the obedience of one man, who was originally born from a virgin, many should be justified and receive salvation. St. Irenaeus, Against Heresies 3.18
For the Lord, taking dust from the earth, moulded man; and it was upon his behalf that all the dispensation of the Lord's advent took place. He had Himself, therefore, flesh and blood, recapitulating in Himself not a certain other, but that original handiwork of the Father, seeking out that thing which had perished. — St. Irenaeus, Against Heresies 5.14
That the Lord then was manifestly coming to His own things, and was sustaining them by means of that creation which is supported by Himself, and was making a recapitulation of that disobedience which had occurred in connection with a tree, through the obedience which was [exhibited by Himself when He hung] upon a tree, [the effects] also of that deception being done away with. — St. Irenaeus, Against Heresies 5.19
These things, therefore, He recapitulated in Himself: by uniting man to the Spirit, and causing the Spirit to dwell in man, He is Himself made the head of the Spirit, and gives the Spirit to be the head of man: for through Him (the Spirit) we see, and hear, and speak. — St. Irenaeus, Against Heresies 5.20
He has therefore, in His work of recapitulation, summed up all things,
both waging war against our enemy, and crushing him who had at the
beginning led us away captives in Adam, and trampled upon his head, as
you can perceive in Genesis that God said to the serpent, “And I will
put enmity between you and the woman, and between your seed and her
seed; He shall be on the watch for your head, and you on the watch for
His heel. — St. Irenaeus, Against Heresies 5.21
The words of St. Irenaeus echo the author of Hebrews:
Since the children have flesh and blood, he too shared in their
humanity so that by his death he might break the power of him who holds
the power of death — that is, the devil — and free those who all their
lives were held in slavery by their fear of death. For surely it is not
angels he helps, but Abraham’s descendants. For this reason he had to be
made like them, fully human in every way, in order that he might become
a merciful and faithful high priest in service to God, and that he
might make atonement for the sins of the people. Because he himself
suffered when he was tempted, he is able to help those who are being
tempted. (Hebrews 2:14-18)
Recapitulation means that what Adam got wrong, Christ put right. And humankind, which was once headed up in Adam, is now headed up in Christ.
Consequently, just as one trespass [Adam’s] resulted in condemnation for all people, so also one righteous act [Christ’s] resulted in justification and life for all people. (Romans 5:18)
For as in Adam all die, so in Christ all will be made alive. (1 Corinthians 15:22)
Paul tells us in Ephesians 1:9-10 that all in heaven and on earth are summed up, headed up, “recapped,” brought to unity, to oneness, in Christ. If Christ is the head, then humankind is the body. St. Gregory of Nyssa understood this very well: “Now the body of Christ, as I have often said, is the whole of humanity.”
This is Recapitulation.
This is Atonement.
This is the Gospel.