How do we know Christ's sacrificial death is sufficient for our sins?

The sufficiency of Christ's sacrificial death is established in Hebrews 9, which declares that it was not by the blood of bulls and goats that sins were taken away, but by the sacrificial offering of Himself. Christ's death fulfilled all righteousness and met the legal demands of God’s justice. Unlike the constant, repeated sacrifices of the Old Testament, which could never fully atone for sin, Christ's single sacrifice is perfect and complete. By taking our sins upon Himself and bearing the full weight of God's wrath, He secured redemption for all whom the Father had given Him.