How do we know that Christ's sacrifice truly put away sin?

The finality of Christ's sacrifice is affirmed in Hebrews 9:26, where it declares that He appeared to put away sin by the sacrifice of Himself. Unlike the repetitive sacrifices of the Old Testament, which could never atone for sin, Christ's one-time offering accomplished what the law could not—permanent redemption for His people. Through His sacrifice, sin has been dealt with decisively, leading to the declaration that our sins are remembered no more, showcasing the sufficiency and effectiveness of His atoning work.