It's been said that the most difficult point in all the study of divinity is understanding the covenant that God made with Israel at Sinai. Is it a legal covenant? Or is it a gracious covenant? Is it a Covenant of Works, or is it a Covenant of Grace? It's difficult to deny that Sinai belongs to the Covenant of Grace. But for those who accept it as such, there are difficult questions to grapple with. One of the most difficult questions is this: If the Mosaic Covenant truly belongs to the Covenant of Grace, how do you explain that the requirement of the Law was perfect obedience? Here's why this question is so difficult: What God requires in the Covenant of Grace is faith; and actually, faith alone. That's God's requirement in the Covenant of Grace. But though some try to deny it, it's obvious from a clear reading of passages such as Galatians 3:10-12 and Romans 10:5 (cf. Deuteronomy 27:26 and Leviticus 18:5) that at Mt. Sinai, God was indeed requiring perfect obedience of Israel. Faith and perfect obedience are two mutually exclusive systems. So, how do you reconcile the tension? How can you defend the fact that Sinai was indeed part of the Covenant of Grace (requiring faith), if it's clear that God required perfect obedience under Moses? Most people don't know it, but the Puritans wrote extensively about this issue in particular. Francis Roberts wrote convincingly on this issue in his massive, 1,700-plus paged magnum opus on the covenants, entitled Mysterium et Medulla Bibliorum (The Mystery and Marrow of the Bible), which he finished in 1657.
Roberts begins by addressing the three other major positions on the Law and Sinai; namely, 1) that the Law was a republication of the Covenant of Works (pp739-45); 2) that the Law was given as a Mixed covenant of works and grace (pp745-48); and 3) that the Law was given as a separate Subservient covenant (pp748-53). He then propounds his own view: that the Mosaic Covenant is one in substance and essence with the Covenant of Grace (pp753ff). The evidence Roberts gives for seeing Sinai as part of the Covenant of Grace include the following: 1) Scripture tells us that the essence or substance of the Mosaic Covenant was the same as the Abrahamic Covenant, which is the Covenant of Grace (cf. Deuteronomy 7:12; 29:10-13); 2) Scripture tells us that the privileges of the Mosaic Covenant were evangelical promises (cf. Exodus 19:4-6 with 1 Peter 2:9); 3) Scripture tells us that God's promise in the Mosaic Covenant is the same as the Covenant of Grace; namely, to be Israel's God (cf. Leviticus 26:12; Deuteronomy 29:13); 4) Scripture tells us that the context of the Mosaic Covenant is the same as the Covenant of Grace; namely, that God gave His Law to those He had redeemed (cf. Exodus 20:1-2); 5) Scripture tells us that the content of the Mosaic Covenant; namely, the Law itself, points us again and again to Christ and the Covenant of Grace through its types and ceremonies, typical mediator, and pardoning of sin; 6) Scripture tells us that the duties required of Israel in the Mosaic Covenant were gospel duties; namely, to love Him with all their hearts and cling to Him; and 7) Scripture tells us that the signs and seals of the Mosaic Covenant (circumcision and the Passover) are the same as in the Covenant of Grace, since they both pointed to Christ who was to come, and are now fulfilled in baptism and the Lord's Supper in the new covenant.
One of the most valuable arguments that Roberts sets forth for taking Sinai as being part of the Covenant of Grace is from Romans 10. Having proven the content of the entire Mosaic Covenant pointed to Christ (the ark, the mercy-seat, the sacrifice, the table of show-bread, and the veil), Roberts goes on to prove that the requirement of the Mosaic Covenant was likewise faith in Christ. He points out that Paul in Romans 10:5-6 contrasts the righteousness of the Law with the righteousness of faith. And yet, to what text did Paul go to describe the righteousness of faith? To the Law itself—for in describing the righteousness of faith, Paul quotes from Deuteronomy 30:11-14. Roberts concludes, “Whence had this description of the righteousness of faith; but from Moses describing the Law or Sinai Covenant? And Paul excellently expounds the words of Moses, as peculiarly intending to set forth the righteousness of faith. We cannot wish a better commentator.” (p767).
Having laid out the evidence for Sinai belonging to the Covenant of Grace, Roberts begins to address the various objections to this view (pp764ff). In doing so, he refers to principles such as that of administration (pp768-70), emphasis (p771), comparison (pp 770,84,86), and abstraction (p767-68; 773-75). The objection that Roberts deals with in most detail is: how does one reconcile the Mosaic Covenant being part of the Covenant of Grace with the fact that the condition required in the Mosaic Covenant seems to be doing rather than believing? In his words: “The condition upon which life and happiness is held forth in the Law or Sinai-Covenant, is perfect doing; for, 'Moses describes the righteousness which is of the Law, that the man who does those things, shall live by them' (Romans 10:5 with Leviticus 18:5; Galatians 3:12). And he denounces a curse upon the least failing: 'Cursed is everyone that continues not in all things which are written in the Book of the Law to do them (Deuteronomy 27:26; Galatians 3:10). But the condition upon which life and happiness is tendered in the Covenant of Faith is believing in Christ (Romans 10:6-12). Doing and believing; works and faith; are two contrary conditions of life; consequently the Law or Sinai Covenant which requires doing unto life cannot be a Covenant of Faith, but must needs be a Covenant of Works.” (p772).
This question Roberts takes to be the most challenging, saying, “This objection, as it is most obvious to everyone that reads the epistles of Paul to the Romans, and to the Galatians; so it is (in my judgement) of greatest difficulty to be clearly and satisfactorily answered.” (p772). Before giving his own answer, Roberts cites the view of the respected John Ball. Quoting Ball, Roberts explains: “These words, 'Do this and live', must not be interpreted as if they did promise life upon a condition of perfect obedience, and for works done in such exactness as is required; but they must be expounded evangelically, describing the subject capable of life eternal, not the cause why life and salvation is conferred.” (pp772-73). Roberts explains that Ball labored to reconcile this tension by understanding these requirements and conditions as describing who are those who will attain to life rather than why they attain to life; showing us who are justified and not why they are justified (pp772-73). But Roberts concludes that this argument doesn't quite measure up. Many passages in Scripture may be interpreted this way, but not the passages being considered here in the Law, for, he says, “Do this and live, has something more in it than those other passages of Scripture alleged by him. They may be interpreted evangelically, but this phrase in the passages objected can hardly be so interpreted.” (p773). This is so, “partly, because doing, in those Scriptures is directly opposed to believing,” and partly because “failings in evangelical obedience are covered, not cursed.” (p773).
Roberts then sets forth his own explanation; namely, that one needs to rightly differentiate between the Law largely and strictly understood (the principle of abstraction). In his words: “Others [interpret these passages] thus, that the Law may be considered, more largely, as comprehending the whole doctrine and administration of the Sinai-covenant, as delivered by Moses on Mount Sinai; [but also] more restrictively, as it is an abstracted rule of righteousness consisting in precepts, threats and promises; holding forth life upon a condition absolutely impossible to lapsed men; viz, perfect and perpetual personal obedience to the Law; but denouncing the curse and death upon the least contrary failing. In the latter sense Paul understands the Law in Romans 10:5 and Galatians 3:12; and in this sense, the righteousness of the Law stands in perfect doing: 'the man that does them shall live in them'. . .In the former sense, which is more complexive and comprehensive, Paul understands the Law in Romans 10:4 and in Galatians 3:23-24; and the Law thus taken is a Covenant of Faith in Christ Jesus, holding out life and happiness only upon condition of believing in Christ. . .To this effect says one, 'The Law in itself considered, exacted perfection of works as the cause of life; but when that was impossible to man by reason of the infirmity of his flesh, it pleased the Lord to make known to his people by the ministry of Moses, that the Law was given, not to detain men in confidence of their own works but to lead them unto Christ'. . .For though the Law of righteousness promise a reward to the keepers thereof; yet after it has shut up all men under sin, it does substitute another righteousness in Christ, which is received by faith, not purchased by merit of works.' [cf. John Ball]. In both the former and latter sense, the word 'Law' seems to be used in that passage, [Romans 3:21-22]: “But now apart from the Law (IE, strictly taken) the righteousness of God has been manifested, being witnessed by the Law (IE, largely taken) and the Prophets, even the righteousness of God through faith in Jesus Christ for all those who believe”. . .[Thus] the Law largely taken, holds forth life on condition of believing in Christ, and in this notion it was given in the Sinai-covenant, which therefore is a Covenant of Faith [IE, Grace]; [but] the Law strictly taken requires perfect doing, and in that sense Moses gave it not, nor is it a Covenant of Faith but of works.” (p773-75).
Roberts had spoken of this distinction earlier: “Now here it is diligently to be observed, that the word 'Law', as used for God's Law given to Moses for Israel on Mount Sinai, is taken, 1) More largely; 2) More strictly; and 3) Most strictly: 1) More largely and generally, for the whole dispensation of all sorts of commandments: Moral, Ceremonial, and Judicial; given and promulged on Mount Sinai. . . 2) More strictly, and specially for the Moral Law, or Ten Commandments, taken complexively with the preface prefixed, and the promises interwoven therein, as God spoke them on Mount Sinai out of the midst of the fire to Israel, and afterwards wrote them, and gave them to Moses. . . 3) Most strictly, and restrainedly; the word [Law] is taken for The Law abstracted from Moses' administration of it, and precisely considered as an abstracted rule of righteousness, holding forth life merely upon terms of perfect and perpetual personal obedience and denouncing death and the curse upon every one, and that without mercy, in case of the least contrary failing. And in this sense the Apostle takes the word [Law] in his dispute about justification by faith and not by the works of the Law; opposing Law to Gospel and to Grace; works to faith; and justification by works, to justification by faith: 'For as many as are of the works of the Law, are under the curse; for it is written, “Cursed is every one that continueth not in all things which are written in the book of the Law to do them.” But that no man is justified by the Law in the sight of God, it is evident; for, “the just shall live by faith.” And the Law is not of faith; but, the man that doth them, shall live in them'. . . In these, and like passages, the word Law is considered in this most restrictive sense, as abstracted and separated from all other additionals in Moses' administration of it. And in this strictest sense, the Law is materially and for substance the same with the Covenant of Works written in Adam's heart in innocency; which can justify none, because none can perfectly keep it; but [it] condemns all mankind. . .” (pp659-660).
It is in this way then, that Roberts explains passages such as Galatians 3:12: “The Law is not of faith.” He says, “That this cannot be meant of the Law absolutely taken, (for then, you see, Paul should contradict himself, who proves the righteousness of faith from the Law, as revealed therein [Romans 10:6ff]; but must needs be intended of the Law in some limited and restrictive sense. That this cannot be meant of the Law, more generally and complexively taken, for the whole Sinai Covenant as dispensed by Moses; for in this sense the Law is of faith, principally intending justification by faith in Christ, as has been proved. But it may be intended of the Law, more strictly and abstractively taken, for the mere preceptive part of the Law, as declarative of, and in substance one with the Law of nature in Adam's heart, and as abstracted from Moses' administration thereof. . . and in this sense the Law is not of faith, nor held forth the righteousness of faith in Christ. . .this Sinai Covenant was in such sort administered, as to press upon them the perfect fulfilling of the Law, as most necessary to life and salvation, denouncing the curse upon the least failing; but withal revealing to them, that this perfect fulfilling of the Law in their own persons being utterly impossible, he was pleased to accept it in Christ their Surety, perfectly fulfilling it on their behalf, and bearing the curse for their offenses, according to the intimation of the many types and ceremonies in the Law. By exacting of them perfect obedience, impossible to them, it takes them off their own seek[ing] for righteousness by their own doing; by representing Christ's perfect obedience and sufferings as a remedy, it teaches them to seek for righteousness by Christ's perfect obedience, through faith in him.” (pp767-68).
In the context of speaking of the Law in the more strict sense, Roberts at times makes reference to how the carnal Jews misunderstood the Law (pp660,768,774). But it's clear that Roberts is not saying that this distinction of the Law in its stricter sense was mistakingly thrust upon the Law by the Jews. No, the Law is properly understood as inherently affirming both a larger and stricter sense. The mistake of the Jews was not in their understanding of what the Law required—but rather in their lack of understanding why the Law in fact required perfect obedience of them. For God's purpose and intention in requiring perfect obedience (in the stricter sense) was never that the Jews might actually attempt to earn life thereby; but rather to break them of all self-righteousness, and to drive them to Christ, who was indeed pictured and promised in the Law in its larger sense. But the Jews cut Christ out of the Law and took it upon themselves to try to actually merit God's favor through the Law. Roberts is not saying that they were mistaken in taking the Law in a strict sense—but rather they were mistaken in failing to also take the Law in its larger sense. The Jews' mistake was not adding to the Law (the strict sense), but rather in taking away from it (cutting Christ out of the Law's larger sense).
Having affirmed the principle of abstraction as a suitable way to resolve this tension, Roberts goes on to supplement this view with a few additional considerations. What Roberts says here in this last section is absolutely full of insight. I personally consider this last section of his to be the single most valuable thing written by any of the Puritans on the nature of the Law and God's design and intention in giving it in the way He did. Roberts thus concludes in this way: “I add therefore, for the unfolding of this mystery more clearly, and for answering of this objection more fully, these few considerations touching the Law or Sinai Covenant, and the condition of life and happiness therein revealed, viz:
1) “That the Sinai-covenant was purposely so dispensed as to tender life and happiness upon two opposite and contrary conditions; viz, works and faith; perfect doing, and believing: a) Upon perfect doing all in the Law: Romans 10:5; Galatians 3:12 with Leviticus 18:5; the curse being denounced against the least failing, Galatians 3:10 with Deuteronomy 27:26. b) Upon believing in Jesus Christ the Messiah promised, Romans 3:21,22 and 10:6-12; compared with Deuteronomy 30:11-14. . .To deny this, which is so clear, will but tend to weaken Paul's authority, [and] to darken many Scriptures both of Moses and Paul, and to strengthen the objection.”
2) “That, in this Sinai-covenant these opposite conditions, of perfect doing under pain of curse and death, and of believing in Christ, are very differently required and revealed. a) Believing in Christ is revealed very sparingly and obscurely; b) perfect doing very frequently and plainly. . .Whence (as Calvin notes) though the whole ministration of the Sinai-covenant belongs to Moses' office; yet that function most properly and peculiarly seems to be ascribed to him, which consisted in teaching what the true righteousness of works was, and what rewards or punishments attend upon the observers or breakers of the Law. . .”
3) “That, though these two conditions of perfect doing, and believing, be thus differently revealed and required in the Sinai-covenant; yet believing in Christ unto life and righteousness was therein chiefly and ultimately intended, and perfect doing only urged upon Israel's subordination and tendency to that believing. . .perfect doing upon pain of curse and death was urged upon Israel only in subordination and tendency to believing and the righteousness of faith, [for]. . .The Scripture, peculiarly the Law, hath hereby concluded all under sin, that the promise by faith of Jesus Christ may be given to them that believe. . .”
4) “That, the condition of perfect doing under pain of curse and death, convincing the sinner of his sin and misery, leaves him hopeless in himself. . .but the condition of believing gives him hope, without himself, in Jesus Christ, to trust to him alone for justification.”
5) “That the Sinai-covenant tendered life and happiness upon these two opposite conditions of perfect doing under penalty of curse and death; and of believing in Christ; because both these conditions were necessarily required to the sinners' happiness: [whether] in the sinner, or the sinners' Surety: a) Perfect doing of all God's Law upon pain of death was required to the sinners' happiness: because God's covenant of Works, at first made with Adam and with all his posterity in him, but broken by them, cannot be eluded or evaded. They m