In the fifth chapter of Romans (vv. 12–21), Paul contrasts two key figures in redemptive history — Adam and Jesus. The former (Adam) is a type of the latter (Jesus), making Jesus a “new Adam” (v. 14). Paul explains how the curse (death) associated with Adam’s fall comes upon the entire human race, while salvation comes to the people of God through the death and obedience of Jesus
(the second Adam).
Paul’s contrast between Adam and Jesus takes place against the backdrop of the creation account (Gen. 1–2), wherein Adam is depicted as both the biological and federal head of humanity. When Adam sinned against God (Gen. 3:6–7), he did so as God’s chosen representative of the human race.
In Romans 5:12, Paul speaks of the consequences of Adam’s rebellion against God: “Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned.” Because sin entered the world through Adam’s act of disobedience, sin and its consequence (death) spread to all. Sin and death are not natural to humanity — they are the result of Adam’s fall. This is why we are born with a sinful nature from which spring actual sins — our own violations of God’s law. To put it another way, we are born as sinners (by nature), and we are guilty for Adam’s sin (imputed to us). This is why death inevitably comes upon the entire human race.
Most English translations of the Bible (including the ESV) end verse 12 with a dash. This is because in verses 13–14, Paul breaks off his discussion of the consequences of Adam’s sin to explain how it impacts humanity before the giving of the Law through Moses. In verses 15–17 Paul returns to the contrast between Adam and Jesus. Although Adam’s act of rebellion brought sin and death, the new Adam (Jesus) undoes the consequences of Adam’s treason: “But the free gift is not like the trespass” (v. 15). The comparison of the free gift and the trespass is a broad one. The damage wrought by Adam pales in comparison to what Jesus Christ has accomplished on behalf of those for whom He dies.
As Paul gets more specific, in verse 15 he notes that “if many died through one man’s trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many.” When used in regard to Adam, the “many” refers to the entirety of the human race. Adam represents every person who has ever lived since he is both the biological and federal head of our race. When Paul refers to the “many” in reference to Jesus, he is speaking of those for whom Christ accomplishes His redemptive work. Adam stands at the head of all of humanity, while Christ stands as the head of God’s elect.
Adam’s sin has disastrous consequences for humanity. We are all born with a sinful nature. We will all die. But Paul does not despair. Where sin is present, God’s grace in Christ abounds all the more! As all die through the act of the first man, God’s grace ensures that salvation comes to all those represented by Christ.
Notice too that “the free gift is not like the result of that one man’s sin. For the judgment following one trespass [that of Adam’s] brought condemnation, but the free gift following many trespasses brought justification. For if, because of one man’s trespass, death reigned through that one man, much more will those who receive the abundance of grace and the free gift of righteousness reign in life through the one man Jesus Christ” (vv. 16–17). What Adam brought upon the human race, Christ has undone. Jesus’ sacrificial death and perfect obedience provide the only ground upon which Adam’s fallen children can be reckoned righteous in Christ and acceptable to God.
In verses 18–19, Paul finally returns to his point in verse 12: “Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. 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. Now the law came in to increase the trespass, but where sin increased, grace abounded all the more, so that, as sin reigned in death, grace also might reign through righteousness leading to eternal life through Jesus Christ our Lord.” Adam’s sin brought down the curse of death upon all humanity. Jesus’ sacrificial death upon the cross pays for our sins. While Adam’s act renders us sinners, through Christ’s act of obedience the many will be accounted “righteous,” as Christ’s perfect righteousness is imputed to us through faith.
There are three transactions in Romans 5:12–21. First, the guilt of Adam’s sin is reckoned to humanity, rendering us all guilty and under the sentence of death. Second, by trusting in Jesus’ death for us, the guilt of our sin is reckoned to Him on the cross — where His death satisfies God’s anger toward us. Third, Christ’s perfect obedience is reckoned to us through faith so that we are regarded as righteous. This is how the new Adam (Jesus) undoes the horrible consequences of the first Adam’s sin.