Catechism of the Catholic Church

II. CHRIST'S REDEMPTIVE DEATH IN GOD'S PLAN OF SALVATION

601 The Scriptures had foretold this divine plan of salvation through the putting to death of "the righteous one, my Servant" as a mystery of universal redemption, that is, as the ransom that would free men from the slavery of sin.³⁹⁷ Citing a confession of faith that he himself had "received",  St. Paul professes that "Christ died for our sins in accordance with the scriptures."³⁹⁸ In particular Jesus' redemptive death fulfils Isaiah's prophecy of the suffering Servant.³⁹⁹ Indeed Jesus himself explained the meaning of his life and death in the light of God's suffering Servant.⁴⁰⁰ After his Resurrection he gave this interpretation of the Scriptures to the disciples at Emmaus, and then to the apostles.⁴⁰¹

"For our sake God made him to be sin"

602 Consequently, St. Peter can formulate the apostolic faith in the divine plan of salvation in this way: "You were ransomed from the futile ways inherited from your fathers... with the precious blood of Christ, like that of a lamb without blemish or spot. He was destined before the foundation of the world but was made manifest at the end of the times for your sake."⁴⁰² Man's sins, following on original sin, are punishable by death.⁴⁰³ By sending his own Son in the form of a slave, in the form of a fallen humanity, on account of sin, God "made him to be sin who knew no sin, so that in him we might become the righteousness of God."⁴⁰⁴