How do we know Jesus' sacrificial death is sufficient for our salvation?

The sufficiency of Jesus' sacrificial death for our salvation is rooted in the biblical truth that He bears the punishment for our sins, which is articulated in Romans 5:1, stating, 'Therefore being justified by faith, we have peace with God through our Lord Jesus Christ.' His death on the cross fulfills the requirements of God’s law, which demands that sin must be punished. By imputed righteousness, believers are legally declared justified, meaning the penalty has been paid in full. This not only provides confidence in their standing before God but also reassures them that Christ's work is complete and perfect, rendering any further sacrifice unnecessary. His death is the climax of God's redemptive plan, making Him the perfect substitute for sinners, a core belief in Reformed theology.