How do we know that Christ's work on the cross was sufficient for our salvation?

The sufficiency of Christ's sacrificial work on the cross is a cornerstone of Reformed theology, as it is rooted in God's preordained plan of salvation. In Hebrews 10:12-14, we see that Christ, having offered one sacrifice for sins, sat down at the right hand of God, signifying the completeness and finality of His atonement. This act not only satisfies God's justice but also secures the eternal redemption of those whom He has chosen, providing believers with assurance that He will not lose any of His sheep (John 6:39). Thus, the efficacy of Christ’s sacrifice is celebrated in the belief that it perfectly reconciles the elect to God.