How do we know that Christ's death is sufficient for our sin?

The sufficiency of Christ's death is affirmed in the Scriptures, where it is stated that He bore the punishment for our sins. 1 John 1:9 assures us that if we confess our sins, He is faithful and just to forgive us and cleanse us. This demonstrates that faith in His atoning sacrifice removes the guilt associated with our sins. Christ, being both fully God and fully man, was able to bear the weight of our sin and endure the wrath of God on our behalf. By His blood, we are justified and declared righteous, which is central to the doctrine of sovereign grace and ensures that there is no condemnation for those in Christ Jesus.