ROMANS 5:15-17: "But the free gift is not like the transgression. For if by the transgression of the one the many died, much more did the grace of God and the gift by the grace of the one Man, Jesus Christ, abound to the many. The gift is not like that which came through the one who sinned; for on the one hand the judgment arose from one transgression resulting in condemnation, but on the other hand the free gift arose from many transgressions resulting in justification. For if by the transgression of the one, death reigned through the one, much more those who receive the abundance of grace and of the gift of righteousness will reign in life through the One, Jesus Christ."
1. An OVERVIEW of Romans 5:15-17: Let's remember the context of Romans 5:15-17. . .
“In [Romans 5:12]. . .[Paul] is concerned to pull back and give you a deeper, a broader background and understanding for what he has taught you so far. He's. . .pulling back and saying, 'Let me explain to you some of the underlying reasons for the purposes of God and why salvation has to be this way. Why it is that you cant save yourself. Why it is that you contribute nothing of your own righteousness to your standing of righteousness before God. Why it is that you have to look away from your works and to look to Jesus Christ.' And so, beginning in Romans, Chapter 5, verse 12, he wants to explain to you the parallels which exist between [Christ, on the one hand, and] our first head—our federal representative— Adam, who fell in his rebellion against God from the state of righteousness and grace which God had blessed him with. And he wants to compare Adam to Jesus Christ so that we might understand, first of all, something of the web of sin that we're involved in, and also some reason again for why we need to flee to Christ alone for salvation. But before he will discuss those parallels between Adam and Christ, he wants to explain a couple of other things, especially the discontinuities between Adam and Christ. He wants it to be very clear that Christ, in what He does to save us, is far more glorious and the fruit of it is far more glorious in comparison to Adam [and] the work that Adam did to bring us into this situation. . . In other words, you can't talk about Adam and Christ and compare them without drawing out the bold contrast that exists between them. And that's exactly what [Paul does here] in verses 15 through 17.”1
2. The CONTRASTS contained in Romans 5:15-17: What are the contrasts in Romans 5:15-17?
Verse 15: It seems that there are two main contrasts in verse 15. The first is between the NATURE of the actions of the two covenant heads: Adam's transgression is contrasted with Christ's gift.2 The second is between the DEGREE of the glory of the actions of the two covenant heads: that is, in Christ, “the grace of God not only negates the operation of judgment but abounds unto the opposite, unto justification and life.”3 The abounding of verse 15 refers to the gift extending “not only to the recovery of what Adam lost [IE, conditional favor], but to blessings which Adam did not possess [IE, everlasting favor].”4 In other words: Jesus didn't come to just make salvation possible again—He came to make it certain. He didn't just recover what Adam had lost—He caused us to inherit what Adam never possessed.
Verse 16: In this verse there also seem to be two main contrasts. The first has to do with the immediate EFFECT of the actions of the two covenant heads: Adam's trespass brought condemnation; Christ's gift brought justification. The second contrast has to do with the POWER of the actions of the two covenant heads: “Christ has done far more than remove the curse pronounced on us for the one sin of Adam; he procures our justification from our own innumerable offenses.”5 In other words: Adam ushered in condemnation and death by one sin; but Christ has obtained justification and life despite countless sins.6
Verse 17: The main contrast in verse 17 seems to be between the ultimate RESULT of the actions of the two covenant heads: the work of Adam resulted in the reigning of death; the work of Christ resulted in a reigning in life. The language here must be carefully noted; the contrast is not merely of the reigning of death and the reigning of life. In Adam, death reigned; but in Christ, it is not life that reigns, but we reign in life. “[Christ] delivers us from the rule of death so radically as to enable us to change places with it and rule over it. . .We become kings, sharing the kingship of Christ, with even death under our feet. . .”7
3. The TRUTHS contained in Romans 5:15-17: What gospel truths do we learn in Romans 5:15-17?
As Paul draws out for us the contrasts between Adam and Christ, he also teaches us in these verses some precious truths about God's grace. As we meditate on verses 15-17, here's what we can see in particular:
A) These verses describe the NATURE of God's grace. When God condemned the world on account of Adam's sin, He was operating according to justice. The wages of sin is death, both for Adam and all his posterity. So, condemnation is rooted in God's justice. But justification is rooted in God's grace—something that Paul mentions three times in verses 15-17.10 In Christ, God has dealt with us in a way that is utterly astonishing. It was out of sheer grace that God ever sent His Son in the first place. He wasn't obligated to do what He did; God didn't have to make a way of salvation for us. And what manner of grace. Again: Not coming merely to offer humanity a second chance at salvation, but coming to win it for us. Not coming just to make salvation possible again for sinners—but coming to make it certain.
B) These verses highlight the CERTAINTY of God's grace. The “much more” of verses 15 and 17 isn't just meant to contrast the actions of Adam and Christ, but to strengthen the foundation of our assurance of salvation in Christ. This phrase “does not express a higher degree of efficacy, but of evidence or certainty. . .If the one event has happened, much more may we expect the other to occur.”11 If imputed sin is a certain reality, much more is imputed righteousness. If it's a certainty that all in Adam are condemned, it's much more of a certainty that all in Christ are justified. If it's certain that death reigns over all in and through Adam, then it's all the more certain that life reigns over all in and through Christ.
C) These verses demonstrate the MEDIATION of God's grace. Verse 17 also makes it really clear that our justification isn't just established on the basis of Christ's righteousness—it's also upheld through the mediation of Christ's righteousness: “For if by the transgression of the one, death reigned through the one, much more those who receive the abundance of grace and of the gift of righteousness will reign in life through the One, Jesus Christ.” Our reigning in life isn't just grounded upon Jesus' righteousness; it's also perpetually upheld through the mediation of His righteousness. In other words, Jesus didn't just accomplish salvation for us—He continues to perpetually uphold that salvation.12 So, our victory in the Christian life isn't contingent on us at all; but on the perpetual mediation of the righteousness of Christ.13
D) These verses define the RECIPIENTS of God's grace. Some people use verses 15-19 to defend universalism, teaching that just as Adam's sin brought condemnation to all (without distinction), so too Christ's righteousness brings justification to all (without distinction). But this view not only contradicts the teaching of Scripture in general; it also opposes the particularity of salvation taught in this very passage. In verse 17 Paul makes clear that it is not all men in general who are justified, but a particular group of people. It is only “those who receive the abundance of grace and of the gift of righteousness” that will reign in life through Jesus Christ. So, God's grace is a gift that must be received through faith in Christ.
1 Ligon Duncan from his course on Covenant Theology.
2 Hodge here poses and answers an important question that relates to verses 15-17. On verse 15: “It is here. . .expressly asserted that the sin of Adam was the cause of all his posterity being subjected to death, that is, to penal evil. But it may still be asked whether it was the occasional or the immediate cause. That is, whether the apostle means to say that  the sin of Adam was the occasion of all men being placed in such circumstances that they all sin, and thus incur death. . .that by being the cause of the corruption of their nature, it is thus indirectly the cause of their condemnation; or  whether he is to be understood as saying that his sin is the direct judicial ground or reason for the infliction of penal evil. . .it is a mere exegetical question. . .Does the dative here express the occasional cause, or the ground or reason of the result attributed to the offense of one man?. . .If Paul says that the offense of one is the ground and reason of the many being subject to death, he says all that the advocates of the doctrine of imputation say. . .[and] this is the strict exegetical meaning of the passage. . .This interpretation is not only possible, and in strict accordance with the meaning of the words, but it is demanded, in this connection, by the plainest rules of exposition. . .” On verse 17: “Here again the dative has a causal force, and the assertion of the apostle is, that the offense of Adam was the cause of death coming on all men. His sin was not the cause of death by any physical efficiency; nor as the mere occasion of leading men to incur by their own act the penalty of death; nor by corruption the nature of man, which corruption is the ground of the inflicted curse; but. . .because his sin was the ground of the judicial condemnation, which passed on all mankind.” Conclusion: “If it is true, therefore, as is so often asserted, that the apostle here, and throughout this passage, states the fact merely that the offense of Adam has led to our condemnation, without explaining the mode in which it has produced this result, it must be because language cannot express the idea.” (Hodge, Romans). As Haldane also says of verse 19: “Adam's disobedience is said not merely to be the occasion of leading his posterity into sin, but to have made them sinners. . .Mr. Stuart makes Adam's sin merely what he calls the instrumental or occasional cause. But with no propriety can Adam's sin be called the instrument by which his posterity sinned . . . an occasional cause is no cause. Every person knows the difference between a cause an an occasion. Besides, to suppose that Christ's own obedience is the real cause of our justification, and that Adam's sin is only the occasion, not properly the cause, of our condemnation, is to destroy the contrast between Adam and Christ, on which the Apostle here insists. If Christ's obedience is the ground of our justification, Adam's disobedience must, by the contrast, be the ground of our condemnation.” (Romans, pp218-219).
3 Quote is from John Murray from his commentary on Romans, p193. Stott focuses on the contrasting nature of the actions; Murray on the degree of their glory; Moo on both. Hodge, Murray, and Moo all further point out that one major thrust of the “much more” of verses 15 and 17 has to do with the certainty of grace bestowed in Christ; we will discuss this later under Heading III, “The Truths Contained in Romans 5:15-17.”
4 From Haldane in his commentary on Romans, p214.
5 Quote from Hodge on his commentary on Romans. Stott focuses on the effect of the two actions; Hodge and Murray on the power of their actions; Moo draws out both aspects.
6 Moo: “For the judicial verdict that resulted in condemnation was from one [transgression], but the gift that leads to justification came after many transgressions.” (p338). Murray: “Judgment. . .take[s] into account only one sin of one man and the whole race is condemned. But the free gift and justification take into account the many sins. . .of a great multitude (p196).
7 Quote from Stott from his commentary on Romans. Haldane put it this way in his commentary on Romans: “Believers are to be kings as well as priests. All this they are to be through the one Jesus Christ; for as they were one with Adam in his fall, so they are one with Christ in His victory and triumph.” (p215). Adding to this idea, Hodge also draws out from verse 17 insights concerning (again) the certainty of grace (as with verse 15), as well as the objects of grace, which we will also deal with below under Heading III, “The Truths Contained in Romans 5:15-17.” (from his commentary on Romans).
8 The “act of grace” refers to the redemption accomplished through Christ's perfect life and atoning death.
9 The “gift of righteousness” refers to the redemption applied by the Spirit.
10 Murray notes in discussing verse 15 that Paul here moves “from the operation of judicial judgment to the bestowments of God's grace. . .The one sin of Adam is the judicial ground or reason for the death of the many. . .[but] the grace of God not only negates the operation of judgment but abounds unto the opposite, unto justification and life.” (Romans, pp192-93).
11 Hodge, Romans.
12 As Isaiah 9:7, “. . .to establish it and to uphold it with justice and righteousness from then on and forevermore. . .”
13 Murray: “the apostle asserts that not only did death reign by reason of 'the trespass of the one' but also through the mediacy of the one. Adam sustained such a relationship to the human race that through him death exercised its universal sway over men. . .the same type of relationship to Christ for those reigning in life is assumed as obtains between Adam and those over whom death reigns. The permanency of the mediation of Christ. . .[is] the condition of the reign in life.” (pp197-98).