The transformation of man into a new creature
In the death and resurrection of Jesus Christ, the new Adam, the renewal of the world awaited at the end of history, the "new heavens and the new earth" announced by the prophets (Is 65,17; 66,22) has already been fulfilled. The new creation, inaugurated by the cross and the glorification of Jesus is an authentic anticipation of the eschatological transformation.
This "new creation" and the "new Adam" do not however represent the abandoning of the first Adam, but rather his redemption, the fullness of his truth and his destiny. The world and mankind in fact were created in anticipation of Jesus Christ, the definitive man. He is the alfa and the omega, the most original truth hidden in the plan of the creation and its final historical fulfilment.
The "new creation" is the result of the incarnation, in which the Son of God unites in Himself human nature, overcoming death and sin with his crucifixion and resurrection, and redeemed man and transformed him into a new creature.
Therefore the beginning of the "new creation" is to be found in "the love of Christ", who "died for us all" and "has risen for mankind" (2 Cor 5,14-15). In this love, Jesus Christ burdens Himself with the sins of the whole world, suffers death (which is a consequence of sin) and manifests the just divine judgement on the old world and on sinners; and, with this same gesture, also makes manifest the mercy of the Father and, at the same time, His infinite love for the Father and for mankind; it is in this manner, in Him, that God reconciled the world with Himself (see 2 Cor 5,19). The Father’s answer to Jesus’ obedience unto death, in which He made the destiny of sinners His own, is His glorious resurrection, which transforms mankind in the fullness of the Holy Spirit, rendering Him "our wisdom, our justification, our sanctification and our atonement" (1 Cor 1,30), so this may "bring to all justification, that is life" (Rom 5,18).
Christ’s human nature, gloriously transformed by the Spirit, is the new and definitive creation. This has been fulfilled through the highest manifestation of God’s love, acknowledged and mutual, witnessed in front of the world and communicated to mankind by Jesus Christ through the consignment of His own life. Redemption and the new creation are therefore merged in the eternal mercy of the Trinity, which however did not wish to fulfil its definitive work without freedom and a human answer, offered by Christ Jesus.
The very reality of this world was overcome by the event Jesus Christ; the criteria that counted in the world, the powers that governed it, the dialectics that moved it, its threats and riches belong to the past, these no longer mean anything at all for Christians, for those who are baptised and merge with Christ: "Circumcision means nothing, the want of means nothing, when a man is in Christ there has been a new creation" (Gal 6,15). Nothing that belongs to this world now constitutes the hope or the glory of Christians: "Nobody therefore should repose his confidence in men, everything is for you: whether it be Paul, or Apollo or Cephas, or the world, or death, or the present or the future; it is all for you! You are for Christ and Christ for God" (1 Cor 3,21-23).
Living in Christ, Christians are freed from the powers of this world, from sin, from death, from the illusions and projects that concern them; in fact, they no longer live for themselves, but for Jesus Christ, the Lord, in virtue of His Spirit (see 2 Cor 5,15; Rom 14,7-8). The fact that they are "in Christ", in communion with His Body, as His members and no longer of this world, is the very condition of the new creature. In Christ, in fact, in His Cross and His resurrection, God has placed the definitive foundations of reality: "all things are in Him" (Col 1,17).
The Church, the Body of Christ, represents in the world the annunciation of reconciliation with God (see 2 Cor 5,18-20), the fulfilment of His plan to recapitulate all things in Christ (see Eph 1,10), the beginning of the new creation.
Humanely, this new creation is made manifest as the reality of mankind’s reconciled unity with God and the entire human race (see LG 1). Supported by the Mercy of the Father, by the death and resurrection of Jesus Christ, by the gift of His Spirit, those who find themselves living "in Christ", incorporated with communion with Him, stand in the midst of the world as Christ’s envoys, without belonging to this world (see John 17,14-17), and live "of a faith that works through mercy" (see Gal 5,6).
In this manner, through the gift of His Spirit, Christ has constituted His brothers as His Body (see LG 7a), a "communion of life, of mercy and of truth" which He takes upon Himself as a "instrument for the redemption of all", sent forth " into the whole world as the light of the world and the salt of the earth" (see LG 9).