How do we know that Christ's death was an accomplishment?

In the sermon, the preacher articulates that Christ's death was not merely an end but a significant achievement. According to the doctrine of substitutionary atonement, Jesus, who knew no sin, voluntarily laid down His life to fulfill the law and satisfy divine justice. His death accomplished justification for all whom the Father had given Him, ensuring their salvation. This is supported by passages that reveal that His sacrificial act successfully paid the penalty for the sins of the elect, affirming that His work on the cross was both complete and salvific, leading to eternal salvation for His people (Romans 3:24-26).