The Law Was Not the Gospel for Adam, but Christ’s Satisfaction of the Law is the Gospel for Us
The real point of the law-gospel antithesis is not “conflict”. It is non-identity. The law is not the gospel. The gospel is not the law. The gospel, however, is about Christ’s satisfaction of God’s law for God’s elect. Though law and gospel are not the same thing, they are not opposed because they never claim to have the same function.
Law says what God demands. Gospel says how Christ satisfied that demand for the elect. The law never offered life off probation: only one sin would put Adam and his seed under its curse, and no matter how many acts of obedience to the law, the law could never promise the life of the age to come.
The law-gospel antithesis does NOT understand Romans 10:4 in terms of abrogation. The “end of the law” is Christ completing all that the law demanded, so that there is no remainder left for the Spirit enabled Christian to do. The gospel says DONE. The gospel does not say “to be done by the life of Christ in the elect”.
Christians sin, and therefore their “fulfillment of the law” (see, for example, Romans 13) cannot ever satisfy the law. But the law will not go unsatisfied.
The law, once satisfied by Christ, now demands the salvation of all the elect. God the Father would not be just, and God the Son would not be glorified, if the distribution of the justly earned benefits were now conditioned on the imperfect faith or works of elect sinners. Yes, faith is necessary for the elect, but even this faith is a gift earned by the righteousness of God in Christ’s work.
This is how the law/gospel antithesis explains Romans 3:31. The law is not nullified but honored by Christ. The only way that its requirements will ever be fully satisfied in the elect (Romans 8:4) is by the imputation of what Christ earned. “
If the law were the gospel, even saying that there’s law (in the garden and now) would be “legalism”. But the law is not the gospel and it was never the gospel. Romans 11:5—“So too at the present time there is a remnant, chosen by grace. But if it is by grace, it is not on the basis of works; otherwise grace would not be grace.”
The legalist identifies law and gospel, and then reduces the demand to including what the Spirit does in the elect. But what God does in us (by grace) must be excluded from the righteousness.
The “covenant of works” theory teaches a ”hypothetical gospel” in which Adam supposedly “could have” earned righteousness for others by keeping the law. One clear way to say that the law is not the gospel is to say that the it was not the gospel for Adam either. But the “covenant of works” is not needed for us to keep the law/gospel antithesis, which antithesis is biblical and important.
Romans 8:3-4 For God has done what the law, weakened by the flesh, could not do. By sending his own Son in the likeness of sinful flesh and for sin,[c] he condemned sin in the flesh, 4 in order that the righteous requirement of the law might be fulfilled in us, who walk not according to the flesh but according to the Spirit.
Smeaton, Apostles Doctrine of the Atonement, p 178–”Romans 8:4–That the righteousness of the law would be fulfilled in us. That is so like another expression of the same apostle, that the two passages might fitly be compared for mutual elucidation (II Cor 5:21). This expression cannot be referred to any inward work of renovation; for no work or attainment of ours can with any propriety of language be designated a “fulfillment of the righteousness of the law”.
The words, “the righteousness of the law,” are descriptive of Christ’s obedience as the work of one for many (Romans 5:18). This result is delineated as the end contemplated by Christ’s incarnation and atonement, and intimates that as He was made a sin-offering, so are we regarded as full-fillers of the law…”
Moo comments on 8:4 in NICNT, p482—”Some think that Christians, with the Spirit empowering within, fulfill the demand of the law by righteous living. However, while it is true that God’s act in Christ has as one of its intents that we produce fruit, we do not think that this is what Paul is saying here.
First, the passive verb “be fulfilled” points not to something that we are to do but to something that is done in and for us. Second, the always imperfect obedience of the law by Christians does not satisfy what is demanded by the logic of this text. The fulfilling of the “just decree of the law” must answer to that inability of the law with which Paul began this sentence. “What the law could not do” is to free people from “the law of sin and death”–to procure righteousness and life. And it could not do this because the “flesh” prevented people from obeying its precepts.
The removal of this barrier consists not in the actions of believers, for our obedience always falls short of that perfect obedience required by the law. As Calvin puts it, “the faithful, while they sojourn in this world, never make such a proficiency, as that the justification of the law becomes in them full or complete. This must be applied to forgiveness; for when the obedience of Christ is accepted for us, the law is satisfied, so that we are counted just.”
If then the inability of the law is to be overcome without an arbitrary cancellation of the law, it can only happen through a perfect obedience of the law’s demands. See Romans 2:13 and our comments there.
In the last part of Romans 8:4, the participial clause modifying “us” is not instrumental—”the just decree of the law is fulfilled in us BY our walking not according to the flesh but according to the Spirit”–but descriptive, characterizing those in whom the just decree of the law as ‘those WHO walk not according to the flesh but according to the Spirit.” Paul does not separate the “fulfillment” of the law from the lifestyle of Christians. But this does not mean that Christian behavior is how the law is fulfilled….”
Steele and Thomas, Romans: an interpretative outline: “In order to free believers from the guilt or condemnation of sin, God sent His own Son into the world (in a nature like man’s sinful nature, but not itself sinful. See Heb. 2:14-18; 4:15). Christ gave Himself as a sacrifice for sin, and thereby legally put sin away and thus freed His people from its guilt. As a result of Christ’s sacrificial work, the just requirement (demand) of the law has been fulfilled (fully met) in those who are joined to Him. This of course is because of the fact that what Christ did, He did as their substitute or representative, and it is therefore counted (imputed) to them as if they themselves did it. (8:4)
Charles Hodge: one’s interpretation of Romans 8 verse 4 is determined by the view taken of Romans 8:3. If that verse means that God, by sending His Son, destroyed sin in us, then, of course, this verse must mean, “He destroyed sin in order that we should fulfill the law” — that is, so that we should be holy (sanctification). But if Romans 8:3 refers to the sacrificial death of Christ and to the condemnation of sin in Him as the sinners’ substitute, then this verse must refer to justification and not sanctification.”
John Gill: “internal holiness can never be reckoned the whole righteousness of the law: and though it is a fruit of Christ’s death, it is the work of the Spirit, and is neither the whole, nor any part of our justification: but this is to be understood of the righteousness of the law fulfilled by Christ, and imputed to us; Christ has fulfilled the whole righteousness of the law, all the requirements of it; this he has done in the room and stead of his people; and is imputed to them, by virtue of a federal union between him and them, he being the head, and they his members; and the law being fulfilled by him, it is reckoned all one as it was fulfilled in, or if by them; and hence they are personally, perfectly, and legally justified; and this is the end of Christ’s being sent, of sin being laid on him, and condemned in him. The descriptive character of the persons in Roman 8:4 is the same with that in Romans 8:1.”