Scripture teaches there are two antithetical ways of receiving something: as a gift or as a debt. “Now to the one who works, his wages are not counted as a gift but as his due.” (Rom 4:4) “But if it is by grace, it is no longer on the basis of works; otherwise grace would no longer be grace.” (Rom 11:6) “But the law is not of faith, rather ‘The one who does them shall live by them.'” (Gal 3:12)
So gift/grace/faith and due/works/law.
From this we develop the distinction between a covenant of grace and a covenant of works. Nehemiah Coxe explained
[R]estipulation [meaning counter-engagement or covenant response] (and consequently, the way and manner of obtaining covenant blessings, as well as the right by which we claim them) necessarily varies according to the different nature and terms of those covenants that God at any time makes with men. If the covenant be of works, the restipulation must be by doing the things required in it, even by fulfilling its condition in a perfect obedience to its law. Suitably, the reward is of debt according to the terms of such a covenant. (Do not understand it of debt absolutely but of debt by compact.) But if it be a covenant of free and sovereign grace, the restipulation required is a humble receiving or hearty believing of those gratuitous promises on which the covenant is established. Accordingly, the reward or covenant blessing is immediately and eminently of grace. (36)
A question then arises about how a promise relates to this dichotomy. It would appear that we could add Galatians 3:18 to the above list of ways of receiving something, adding promise as a synonym for gift/grace/faith. “For if the inheritance comes by the law, it no longer comes by promise; but God gave it to Abraham by a promise.” (Gal 3:18 ESV)
On this basis, some men have argued for a distinction between a covenant of promise and a covenant of law. Lee Irons notes “In By Oath Consigned Meredith Kline distinguishes between ‘promise covenants’ and ‘law covenants’ (BOC 16)… Kline makes the same distinction in Kingdom Prologue, although he uses more traditional terminology, substituting “covenants of works/grace” for “law/promise covenants” (KP 5).” Galatians 3:18 was central to Kline’s argument.
Paul found the difference between two of the Old Testament covenants to be so radical that he felt obliged to defend the thesis that the one did not annul the other (Gal. 3:15ff.). The promise of God to Abraham and his seed (cf. Gen. 13:15; 17:8) was not annulled by the law which came later (Gal. 3:17). The chronological details show that Paul was contrasting the promise covenant not to some general law principle but to the particular historical administration of law mediated through Moses at Sinai after Israel’s 430 years in Egypt… The Sinaitic administration, called “covenant” in the Old Testament, Paul interpreted as in itself a dispensation of the kingdom inheritance quite opposite in principle to inheritance by guaranteed promise: “For if the inheritance is by law, it is no longer by promise” and “the law is not of faith; but, He that doeth them shall live in them” (Gal. 3: 18a and 12; cf Lev. 18:5)… we must recognize that, according to Paul, it was this specific covenantal entity, the Sinaitic Covenant as such, that made inheritance to be by law, not by promise—not by faith, but by works. (BOC 22-23)
On this basis, Kline identified the Abrahamic and New Covenants as one, in distinction from the Old Sinaitic Covenant. Kline’s argumentation is much more detailed, but a problem begins to emerge when we look closer at the idea of a covenant promise. Hebrews 8:6, for example, notes that the New Covenant is better than the Old Covenant, not because it is a promise covenant, but because its promises are better than the promises of the Old Covenant. Owen explains that
[E]very covenant between God and man must be founded on and resolved into “promises.”… It is necessary from the nature of a covenant… And herein lies the great difference between the promises of the covenant of works and those of the covenant of grace. The first were only concerning things future; eternal life and blessedness upon the accomplishment of perfect obedience. Promises of present mercy and pardon it stood in need of none, it was not capable of. Nor had it any promises of giving more grace, or supplies of it; but man was wholly left unto what he had at first received. Hence the covenant was broken. But in the covenant of grace all things are founded in promises of present mercy, and continual supplies of grace, as well as of future blessedness…
The promises of the covenant of grace are better than those of any other covenant, as for many other reasons, so especially because the grace of them prevents any condition or qualification on our part. —I do not say the covenant of grace is absolutely without conditions, if by conditions we intend the duties of obedience which God requireth of us in and by virtue of that covenant; but this I say, the principal promises thereof are not in the first place remunerative of our obedience in the covenant, but efficaciously assumptive of us into covenant, and establishing or confirming in the covenant. The covenant of works had its promises, but they were all remunerative, respecting an antecedent obedience in us; (so were all those which were peculiar unto the covenant of Sinai). They were, indeed, also of grace, in that the reward did infinitely exceed the merit of our obedience; but yet they all supposed it, and the subject of them was formally reward only. In the covenant of grace it is not so; for sundry of the promises thereof are the means of our being taken into covenant, of our entering into covenant with God. The first covenant absolutely was established on promises, in that when men were actually taken into it, they were encouraged unto obedience by the promises of a future reward. But those promises, namely, of the pardon of sin and writing of the law in our hearts, which the apostle expressly insisteth upon as the peculiar promises of this covenant, do take place and are effectual antecedently unto our covenant obedience. For although faith be required in order of nature antecedently unto our actual receiving of the pardon of sin, yet is that faith itself wrought in us by the grace of the promise, and so its precedency unto pardon respects only the order that God had appointed in the communication of the benefits of the covenant, and intends not that the pardon of sin is the reward of our faith.
So the fact that an inheritance is given in covenant by promise does not mean that it is given as a gift by grace through faith. An inheritance given in covenant by promise can be given as debt for works of the law. WCF 19.1 “God gave to Adam a law, as a covenant of works, by which he bound him and all his posterity to personal, entire, exact, and perpetual obedience; promised life upon the fulfilling, and threatened death upon the breach of it; and endued him with power and ability to keep it.” But if that is true, then how are we to understand Paul when he says “For if the inheritance comes by the law, it no longer comes by promise; but God gave it to Abraham by a promise.” (Gal 3:18 ESV)?
I believe the answer lies in reading v18 not as a generic statement about law inheritance vs promise inheritance, but rather a specific statement about inheritance through the Sinai law vs inheritance through the promised Messiah. The NET says “For if the inheritance is based on the law, it is no longer based on the promise, but God graciously gave it to Abraham through the promise.”
Let’s back up all the way to 2:21 “I do not nullify the grace of God, for if righteousness were through the law, then Christ died for no purpose.” This leads into what Paul argues in chapter 3.“And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, ‘In you shall all the nations be blessed.'” This justifying faith of Abraham is antithetical to justifying works because “all who rely on works of the law are under a curse; for it is written, ‘Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.'” Therefore “the law is not of faith, rather ‘The one who does them shall live by them.'” Returning to 2:21, righteousness cannot come through the law of Sinai, because if it came through the law of Sinai, then Christ died for no purpose. But God swore (promised) that Christ would come and die for a purpose. Therefore righteousness cannot come through the law of Sinai.
“To give a human example, brothers: even with a man-made covenant, no one annuls it or adds to it once it has been ratified. Now the promises were made to Abraham and to his offspring.” Paul is referring to the promise mentioned in v8 “In you shall all the nations be blessed.” What does “In you” refer to in that promise? It refers specifically to the Messiah, Abraham’s seed. “It does not say, ‘And to offsprings,’ referring to many, but referring to one, ‘And to your offspring,’ who is Christ. This is what I mean: the law, which came 430 years afterward, does not annul a covenant previously ratified by God, so as to make the promise void.” This covenant promise was that in Christ all the nations would be justified. But if the nations could be justified through the law of Sinai, then Christ died for no purpose, which would make the promise void.“For if the inheritance [righteousness] is based on the law [of Sinai], it is no longer based on the promise [of Christ], but God graciously gave it [righteousness] to Abraham through the promise [of Christ]” referring to how God “preached the gospel beforehand to Abraham, saying, ‘In you shall all the nations be blessed'” and “Abraham ‘believed God, and it was counted to him as righteousness.'”
19th century Scottish Presbyterian turned baptist James Haldane said
It is indeed said, that “the scripture foreseeing that God would justify the heathen through faith preached before the gospel to Abraham, saying, In thee shall all nations be blessed,” Gal. iii. 8. But this was merely a declaration of all nations being blessed in Jesus, who was Abraham’s seed. The covenant is said to have been confirmed of God in (rather concerning, eis Christon*) Christ; for there is no doubt that Christ, springing from the loins of Abraham, was the great promise made to him. Hence, it is opposed to the law, and called the promise, Gal. iii. 18… This was a promise that the Savior, revealed immediately after the fall, Gen. iii. 15. should spring from him. To this promise the apostle alludes, when he says “Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many, but as of one, and to thy seed, which is Christ,” Gal. iii. 16.
To call this the covenant of grace, is only calculated to mislead; for surely it was peculiar to Abraham that Christ should spring from him… [A]lthough an oath was made to Abraham, securing the blessing to all families of the earth through him, this does not prove that the covenant made with him was the new covenant
*See Whitby, Macknight, &c. The covenant of God concerning Christ was the promise, that in Abraham all families of the earth should be blessed, Gen. xii. 3. This was afterwards confirmed by an oath, Heb vi. 17.
Therefore Galatians 3:18 does not teach that inheritance by promise is synonymous with inheritance by gift/grace/faith in distinction from inheritance by due/works/law. Therefore Galatians 3:18 does not teach a distinction between a covenant of promise and a covenant of law. Therefore Galatians 3 does not establish the unity of the Abrahamic and New Covenants in distinction from the Sinai Covenant. Therefore the Abrahamic Covenant may, in fact, be a covenant of law/works for the typical kingdom of Abraham’s carnal offspring in unison with the Sinai Covenant.
For more on this, see
- Galatians 3:16
- Some Disagreement with Coxe on Galatians 3:17
- the “Abrahamic Covenant” section on the Welcome page