A Commentary by John Stott
The apostle Paul is still expounding ‘the truth of the gospel’, namely that salvation is a free gift of God, received through faith in Christ crucified, irrespective of any human merit. He is emphasizing this, because the Judaizers could not accept the principle of *sola fides*, ‘faith alone’. They insisted that men must contribute something to their salvation. So they were adding to faith in Jesus ‘the works of the law’ as another essential ground of acceptance with God.
The way Paul hammers home God’s plan of free salvation is from the Old Testament. In order to understand his argument, and to feel its force, we need to grasp both the history and the theology which lie behind its reasoning.
Paul takes us back to about 2000 BC, to Abraham, and then on to Moses who lived some centuries later. Moses is not named here, but he is without doubt the ‘intermediary’ (verse 19), through whom the law was given.
Let me remind you of this part of the Old Testament story. God called Abraham from Ur of the Chaldees. He promised that He would give him an innumerable ‘seed’ (or posterity), that He would bestow on him and on his seed a land, and that in his seed all the families on earth would be blessed. These great promises of God to Abraham were confirmed to Abraham’s son Isaac, and then to Isaac’s son Jacob. But Jacob died outside the promised land, in Egyptian exile, to which a famine in Canaan had driven him. Jacob’s twelve sons died in exile too. Centuries passed. A period of 430 years is mentioned (verse 17), which refers not to the time between Abraham and Moses, but to the duration of the bondage in Egypt (Ex.12:40; cf. Gn. 15:13; Acts 7:6). Finally, centuries after Abraham, God raised up Moses, and through him both delivered the Israelites from their slavery and gave them the law at Mount Sinai. This, briefly, is the history which links Moses to Abraham.
b). The theology.
God’s dealings with Abraham and Moses were based on two different principles. To Abraham He gave a promise (‘I will show you a land…I will bless you…’, Gn.12:1, 2). But to Moses He gave the law, summarized in the Ten Commandments. ‘These two things (as I do often repeat),’ comments Luther, ‘to wit, the law and the promise, must be diligently distinguished. For in time, in
place, and in person, and generally in all other circumstances, they are separate as far asunder as heaven and earth…’ Again, ‘unless the Gospel be plainly discerned from the law, the true Christian doctrine cannot be kept sound and uncorrupted.’ What is the difference between them? In the promise to Abraham God said, ‘I will…I will…I will…’ But in the law of Moses God said, Thou shalt…thou shalt not…’. The promise sets forth a religion of God – God’s plan, God’s grace, God’s initiative. But the law sets forth a religion of man – man’s duty, man’s works, man’s responsibility. The promise (standing for the grace of God) had only to be believed. But the law (standing for the works of men) had to be obeyed. God’s dealing with Abraham were in the category of ‘promise’, ‘grace’ and ‘faith’. But God’s dealings with Moses were in the category of ‘law’, ‘commandments’ and ‘works’.
The conclusion to which Paul is leading is that the Christian religion is the religion of Abraham and not Moses, of promise and not law; and that Christians are enjoying today the promise which God made to Abraham centuries ago. But in this passage, having contrasted these two kinds of religion, he shows the relation between them. After all, the God who gave the promise to Abraham and the God who gave the law to Moses are the same God! Some commentators think that this is the meaning of the emphatic phrase ‘God is one’ (verse 20), namely that the God of Abraham and the God of Moses are one and the same God. We cannot set Abraham and Moses, the promise and the law, against each other, accepting the one and rejecting the other, *tout simple*. If God is the author of both, He must have had some purpose for both. What, then is the relation between them?
Paul divides his subject into two parts. Verses 15-18 are negative, teaching that the law did not annul the promise of God. Verses 19-22 are positive, teaching that the law illuminated God’s promise and actually made it indispensable. The first part Paul enforces by an illustration from human affairs, and the second by answering two questions.