Catechism of the Catholic Church
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
603 Jesus did not experience reprobation as if he himself had sinned. 405 But in the redeeming love that always united him to the Father, he assumed us in the state of our waywardness of sin, to the point that he could say in our name from the cross: "My God, my God, why have you forsaken me?" 406 Having thus established him in solidarity with us sinners, God "did not spare his own Son but gave him up for us all", so that we might be "reconciled to God by the death of his Son". 407
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.