Theologians often speak of two aspects of the obedience that Jesus rendered throughout his life. On the one hand, his passive obedience was his submission to a life of humiliation and suffering, culminating in his crucifixion. His death on the cross satisfied God’s just requirement that sin be punished by death. In his passive obedience, Jesus was our substitute. He allowed our guilt to be imputed to him, that is, reckoned to his account. And once he was thereby counted guilty in God’s eyes, he died in our place. This single act paid the penalty for all our sins, so that God’s judgment and wrath no longer threaten us. It obtained the forgiveness of our sins, and freed us from the penalty of the law. As Paul wrote in Romans 5:18-19:

Just as the result of one trespass was condemnation for all men, so also the result of one act of righteousness was justification that brings life for all men. For just as through the disobedience of the one man the many were made sinners, so also through the obedience of the one man the many will be made righteous.

Here, Paul explicitly compared Adam and Jesus. And his point was that because Jesus represents us in the same way that Adam once represented us, Jesus’ sacrifice on the cross frees us from God’s just condemnation, and causes him to see us as righteous.

The second type of obedience Jesus rendered was active obedience. This was his life of obedience to everything the Father commanded. In his incarnation, Jesus perfectly kept God’s law. He never sinned, and he always did what God commanded. And in the same way that our guilt was imputed to Jesus on the cross, his righteous obedience is imputed back to us. Theologians often call this “forensic righteousness”, meaning that we are declared to be righteous even though we haven’t yet been completely freed from the indwelling presence of sin. God looks at us as if we were his incarnate Son, Jesus — as if we had lived his perfect life, and performed all his good works ourselves. As a result, our fellowship with God is restored. And although depravity still prevents us from earning salvation ourselves, God rewards us with the blessings of salvation on the basis of Jesus’ merit.

For us to be redeemed out of our sinful, fallen state as “children of wrath,” as the Bible says, we need God to solve our problem. We’re helpless, hopeless, unable to solve our own problem of sin. But God in his grace solves our problem. And the way he does that is by sending his Son to represent us. God the Son becomes a man and lives a perfect life of obedience, dies a perfect death on the cross, and then walks out of a tomb, defeating death for us. And the only way we then can be redeemed is to be part of this new creation, this firstfruits of resurrected redeemed life that Jesus represents. And the way we become part of that is by trusting him. So, it’s faith in Christ, the God-man who represents us in his redeeming work, that we find redemption. [Dr. K. Erik Thoennes]