"For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him." 2 Corinthians 5:21
Our blessed Lord offered himself for sin; that is, that he might put away sin by the sacrifice of himself—"Who his own self bare our sins in his own body on the tree" (1 Pet. 2:24). It was absolutely necessary either that the sinner should suffer in his own person, or in that of a substitute. Jesus became this substitute; he stood virtually in the sinner's place, and endured in his holy body and soul the punishment due to him; for he "was numbered with the transgressors." He thus, by the shedding of his most precious blood, opened in his sacred body a fountain for all sin and all uncleanness (Zech. 13:1). The cross was the place on which this sacrifice was offered; for as the blood of the slain lamb was poured out at the foot of the altar, sprinkled upon its horns, and burned in its ever-enduring fire, so our blessed Lord shed his blood upon the cross.
He there endured the wrath of God to the uttermost; he there put away sin by the sacrifice of himself; he there offered his holy soul and body, the whole of his pure and sacred humanity, in union with his eternal Deity, as an expiation for the sins of his people. Thus all their sin was atoned for, expiated, put away, blotted out, and will never more be imputed to them. This is the grand mystery of redeeming love and atoning blood. Here the cross shines forth in all its splendour; here God and man meet at the sacrifice of the God-man; and here, amidst the sufferings and sorrows, the groans and tears, the blood and obedience of God's dear Son in our nature, grace reigns through righteousness unto eternal life.