How do we know the sacrifice of Jesus is sufficient for our sins?

In contrast to the Old Testament priests, who constantly offered sacrifices but could never take away sins, Jesus offered Himself once and for all. Hebrews 10:11-12 highlights this distinction: 'Every priest standeth daily...but this man...sat down on the right hand of God.' His seating position symbolizes that the work has been completed—God's justice is satisfied, and no further sacrifice is needed. This assurance underscores the gospel of grace, emphasizing that believers can rest in the sufficiency of Christ's atonement.