The message of salvation is the story of two Adams. "For as by the one man's disobedience the many were made sinners, so by the one man's obedience the many will be made righteous" (Rom. 5:19). What the first Adam undid, the second Adam repairs. But who is this second Adam, and what kind of person must He be to do this? Why is He—and only He—able to obey in this way?
The Chalcedonian Creed (AD 451) says the purpose of the incarnation was "for us and for our salvation." The creed is a statement of profound truths about the person of Christ that have been embraced by the church and form the bedrock of how we understand the work of Christ. Unless we understand who Jesus is, we will fail to see the wonder of what He has done to save us.
Obedient in His Human Life
In Romans 5:19, the similarities and dissimilarities between Adam and Christ highlight important aspects of Christ's person. Let's start with a similarity, then consider a dissimilarity, and come back, finally, to a further similarity.
First similarity: it is not incidental that Adam and Christ are both men. It is necessary that our Savior be a man, truly human like us. Scripture is clear that God is the only Savior, and yet, because humans have sinned, God's justice demands that only a human can pay for sin. In the words of the Heidelberg Catechism, because of His righteousness, "God will not punish another creature for what a human is guilty of" (Q&A 14). This is stunning. If God saved us without punishing a human being, it could have destroyed the moral fabric of the universe. We need a Savior who is human. The creed makes clear that when the eternal Son, "begotten before all ages of the Father," joined Himself to human nature in the womb of the virgin, that same Son—our Lord Jesus Christ—was "truly God and truly man, of a reasonable soul and body . . . in all things like unto us." He was not a divine being who appeared to be human. Jesus was not "God in human skin." He was a man, fully human in every way.
But the creed also adds a crucial point: "in all things like unto us, without sin."As the Heidelberg Catechism puts it, "God's justice demands that human nature, which has sinned, must pay for its sin; but a sinner could never pay for sin" (Q&A 16). To be a fallen human being is to "increase our guilt every day" (Q&A 13). We need a Savior who is like us (human) to be able to pay for sin, and we need a Savior who is unlike us (sinless) for this payment to be acceptable to God.
This is where the dissimilarity between the work of Adam and the work of Christ flows from a proper understanding of the person of Christ. It is common in modern theology to argue that in taking on a human nature, the Son of God took on fallen human nature. The assertion is that because we have fallen natures, Jesus cannot be truly like us unless He also has a fallen human nature. But this short-circuits the magnificent beauty of Christ's obedience. Fallenness is not intrinsic to being human; if it were, Adam would not have truly been a man. The Word became flesh to go right back to the very beginning, so to speak, and to do as a man what Adam failed to do. In the womb of His mother, He is both completely identified with us—being fully human—and distinct from us—being free of all Adamic guilt. The language of the Spirit "overshadowing" Mary in the miracle of the incarnation (Luke 1:35) hints at both new creation and new exodus themes. It is best to say that Christ re-lives Adam's life not from the point of the fall onward but from the point of creation onward. He is the new Adam and the new Israel, facing their temptations and fighting their battles, except He triumphs at every point where they failed.
And so we come full circle to another similarity between Adam and Christ in Romans 5:19. Neither is a private individual. They do not act alone. What each one does, he does for those who belong to him. Like a husband as head of his wife is fully responsible for her welfare, so Adam and Jesus as heads of their families bear complete responsibility for them. The actions of the one implicate those who are theirs, either in disobedience or in righteousness. Just as Adam made all who are in him sinners, so Christ makes all who are in Him righteous. How does He do this?
Obedient in His Substitutionary Death
Evangelicals are sometimes guilty of reducing the message of salvation to Christ's atoning death without describing how or why it atones. In fact, the obedience of Christ is the overarching biblical concept for explaining how Christ saves us.
When the author of Hebrews brings the discussion of Christ's priestly work to a climax in chapter 10—after telling us that the animal sacrifices of the old covenant only reminded the worshiper of his sins and did not remove his guilt—he makes a surprising point: sacrifices and offerings were not what God wanted anyway. "Sacrifices and offerings you have not desired" (Heb. 10:5, quoting Ps. 40:6). This is surprising, of course, precisely because the sacrificial system was instituted by God Himself. But the next lines explain what is going on in this passage:
Sacrifices and offerings you have not desired, but a body you have prepared for me; in burnt offerings and sin offerings you have taken no pleasure. Then I said, "Behold, I have come to do your will, O God, As it is written of me in the scroll of the book." (Heb. 10:5-7; Ps. 40:6-8)
God wants human beings who are covenant partners, who do His will. Delighted devotion, wholehearted love, humble submission, and joyful, intimate relationship—this is what Adam was invited to return to God. What God sought from the very beginning was pristine shalom, covenantal wholeness, in the garden and to the ends of the earth; what His covenant partner returned instead was pride, suspicion, unbelief, and rebellion—and all was lost. The sacrificial system was instituted to remedy the problem of human disobedience, but it could not produce human obedience. Yet what about the second Adam? Wonderful beyond words is the fact that before He came to die, Jesus came to live.
We know from the book of Leviticus that the sacrificial rites contained thanksgiving offerings and guilt offerings. Thanksgiving offerings relate to the kind of life God always intended humanity to live in His presence and are what Adam should have offered in the garden; guilt offerings become necessary only after the fall and relate to the kind of life we now experience. In the second Adam, we see the fulfillment of both types of sacrifice. Throughout His whole life, Christ offered Himself as a sacrifice of praise to His Father—"I have come to do your will"—and in His death, He offered Himself as a sacrifice of atonement for sin. The life Jesus lived prepared for the death He died because His obedience reached its climax in His crucifixion (Phil. 2:8).
Here, a glorious truth about the person of Christ—"truly God and truly Man"—sheds light on the wonderful truth that He saves us from eternal loss. Philippians 2:5-11 makes clear that the obedient self-offering of Jesus is not just the offering of a human life. He who died remains "in very nature God." The Heidelberg Catechism says, "no mere creature can bear the weight of God's eternal anger against sin and release others from it" (Q&A 14). Sin against an infinite God requires an infinite payment, but a finite human cannot render this to God outside of an eternal hell. (And even in a hell of eternal duration, finite sinners never reach the point where the payment is complete because the finite cannot pay the infinite price.) We need a Savior who is more than a man. Christ's death, because of who He is as the God-man, is of infinite value and fully satisfies the righteous demands of an infinitely holy God. We can see how closely the doctrines are connected to each other. To concede that hell is not eternal punishment would be to concede that Jesus did not need to be divine in His self-offering on the cross.
Theologians talk about the offering of Christ's life as His active obedience and the offering of His death as His passive obedience, and both are necessary to save us. In His death, Christ gave Himself up and received the judicial punishment for sin (passive), but He was an acceptable offering because He was a guilt-free and wholly obedient man (active), and so was worthy of taking the place of guilt-laden, thoroughly disobedient sinners. John Calvin said that "from the time when he took on the form of a servant, Christ began to pay the price of liberation in order to redeem us." Notice how Calvin's words anticipate the creed. The divine Son joined human nature to Himself, and He did it for us and for our salvation. He came to live and die obediently. His obedience makes not just forgiveness possible, but righteousness available. Because He is our representative head, Christ's obedience is ours.