The act of redemption and atonement for sin which Christ won for us by the pouring out of his Blood on the cross, by his obedient love "even to the end" (Jn 13:1) (433, 616, 1475). The expiation of sins continues in the mystical body of Christ and the communion of saints by joining our human acts of atonement to the redemptive action of Christ, both in this life and in Purgatory.