How do we know Jesus' sacrifice fulfills the requirement for sin?

The necessity of Jesus' sacrifice is rooted in the Reformed understanding of original sin and its consequences. Because sin entered the world through one man, humanity required a perfect substitute who could bear the penalty for sin. In taking on human flesh, as highlighted in Hebrews 2:9, Jesus identified with our human condition, experiencing suffering and death. This act was essential not only for fulfilling God's justice but also for demonstrating His mercy as a loving Savior.

The Bible confirms in passages like Isaiah 53:5 that He was pierced for our transgressions and crushed for our iniquities, reiterating the purpose of Jesus' coming as being to serve as the perfect Lamb of God who takes away the sins of the world (John 1:29). His resurrection further solidifies the truth of His sacrifice, proving that He conquered sin and death once and for all, providing believers not only with forgiveness but also with the hope of eternal life. Therefore, we know Jesus' sacrifice is sufficient because of His unique nature as both fully God and fully man, and because it fulfills God’s redemptive plan laid out in Scripture.