How do we know Christ's substitutionary work is true?

The doctrine of Christ's substitutionary work is central to the Reformed faith. As articulated in Hebrews 2:9, Jesus Christ tasted death for every man, meaning He suffered in the stead of those He came to save. This unique role as our substitute is rooted in God's eternal plan as described in Isaiah 53, where the suffering servant bears our griefs and carries our sorrows. The historical reality of Christ's death and resurrection serves as the foundation for our assurance, as He was raised and crowned with glory, demonstrating that He triumphed over the ultimate consequence of sin—death. Moreover, the accuracy of this doctrine is upheld by the fulfillment of Old Testament prophecies, affirming that God's plan for redemption through Christ is both coherent and divine.