How do we know Christ's sacrifice was sufficient for our sins?

The sufficiency of Christ's sacrifice is rooted in the understanding that He bore the weight of every sin we commit, not overlooking any infraction—big or small. Hebrews 9:26 affirms that Christ appeared to put away sin by the sacrifice of Himself. The perfection of His life and the completeness of His sacrifice ensure that all our sins—past, present, and future—are dealt with and fully atoned for. His cry of 'It is finished' signifies that the work of salvation was wholly accomplished, leaving nothing lacking for those who believe. The infinite value of His blood, as the Son of God, guarantees that His atonement is sufficient for all who are elect, as declared in Scripture.