Promise before law: Abraham's offspring and the sons of God

These chapters continue the defence of the gospel begun in chapters 1 and 2. The Gentile believers of Galatia had received the Spirit and joined the churches by faith. Other teachers then told them that to be true descendants of Abraham and heirs of God's promises they must be circumcised and keep the law of Moses. Paul's reply is an argument from Scripture, and because he does not state the opponents' case directly, readers reconstruct it from his answers. The destination (North or South Galatia) and the date (somewhere between about AD 48 and the mid-50s) are debated, as the previous class explained. What matters here is that the audience was mostly Gentile, had been taught from the Greek Old Testament (the Septuagint), and could follow an argument about Abraham.

The Jewish background is Abraham's central place in Israel's identity. God had promised Abraham land, a great name, offspring and blessing to all the nations (Genesis 12:1-3; 15; 17). Circumcision was the sign of the covenant with Abraham (Genesis 17), and the troublers could argue from Genesis that Gentiles needed it. Paul answers from the same book: Abraham was counted righteous in Genesis 15 before he was circumcised in Genesis 17, and the Mosaic law came centuries later at Sinai.

The tone of these chapters moves from rebuke ('You foolish Galatians', 3:1) to tenderness (4:19, where Paul describes himself as a mother in labour for them) and back to a hard argument. The rhetoric reflects the pastoral crisis: Paul fears he has wasted his labour on them (4:11).

The chapters are argument, and Paul argues the way a Jewish teacher of Scripture of his day would: by quoting texts, linking them, and drawing out their implications. Recognising the moves makes the reasoning easier to follow. In 3:6-14 he links Genesis 15:6 ('Abraham believed God and it was credited to him as righteousness'), Genesis 12:3, Habakkuk 2:4, Leviticus 18:5, Deuteronomy 27:26 and Deuteronomy 21:23. In 3:15-18 he argues from the legal practice of covenants (a ratified covenant cannot be annulled or added to). In 3:16 he builds an argument on the singular of the word 'seed' in the Genesis promises. Interpreters note that the Hebrew word is a collective singular, so the argument either reads the promise as pointing to one descendant, finally Christ, or uses a Jewish exegetical method to show Christ as the representative of the whole people. In 3:29 Paul himself says that all who belong to Christ are Abraham's seed, so the two senses belong together.

The chapter must also be read within the story of salvation history: promise to Abraham, law at Sinai, Christ at the fullness of time (4:4). Paul's talk of the law as a 'guardian' belongs to this story and is not a general verdict that the law is bad; in 3:21 he says plainly that the law is not opposed to God's promises. Finally, 4:21-31 is called an allegory (4:24). Paul does not claim this is the original sense of Genesis, but he reads the story typologically to show a pattern in how God has acted. Such a reading rests on the earlier argument and is not the foundation of it.

Chapter 3:1–5

Paul asks who has bewitched them, when Jesus Christ was publicly portrayed as crucified before their eyes. His question is simple: did you receive the Spirit by works of the law or by hearing with faith? Having begun in the Spirit, are they now being perfected in the flesh? The receiving of the Spirit was the experiential proof of their acceptance.

Chapter 3:6–14

Abraham believed God and it was credited to him as righteousness. So those who have faith are sons of Abraham. Scripture foresaw that God would justify the Gentiles by faith and preached the gospel to Abraham beforehand: in you all nations will be blessed. Those who rely on works of the law are under a curse, since Deuteronomy 27:26 curses everyone who does not keep all the things written in the law. The law is not based on faith but on doing (Leviticus 18:5). Habakkuk 2:4 says that the righteous will live by faith. Then comes the turn: Christ redeemed us from the curse of the law by becoming a curse for us, as it is written, cursed is everyone who hangs on a tree (Deuteronomy 21:23). The purpose was that the blessing of Abraham might come to the Gentiles and that we might receive the promised Spirit through faith.

Chapter 3:15–22

Paul takes an example from everyday life. Even a human covenant, once ratified, cannot be set aside or added to. The promises were spoken to Abraham and to his seed. The law, which came 430 years later (the figure follows Exodus 12:40), cannot cancel a covenant already ratified by God. If the inheritance came by the law, it would no longer come by promise, but God granted it to Abraham by promise. Why then the law? It was added because of transgressions until the seed should come, ordained through angels by a mediator. The reference to angels reflects a Jewish tradition about the giving of the law (also Acts 7:53; Hebrews 2:2). The law is not against the promises, but it could not give life. Scripture has imprisoned everything under sin so that the promise might be given to those who believe.

Chapter 3:23–29

Before faith came, they were held under the law, as in the custody of a paidagogos. In the Greco-Roman household this was a trusted slave who supervised a child's conduct until adulthood; he was not a teacher in the modern sense. So the law was a guardian until Christ. Now through faith all are sons of God in Christ Jesus, as many as were baptized into Christ have put on Christ. Then comes the statement, there is neither Jew nor Greek, slave nor free, male nor female, for you are all one in Christ Jesus. If you belong to Christ, you are Abraham's offspring, heirs according to promise.

Chapter 4:1–7

A child who is heir is no better than a slave while under guardians until the date set by his father. So we were enslaved under the elements of the world. But when the fullness of time came, God sent his Son, born of a woman, born under the law, to redeem those under the law, so that we might receive adoption as sons. Because we are sons, God sent the Spirit of his Son into our hearts, crying 'Abba! Father!' The Aramaic word 'Abba' is the intimate address that Jesus himself used (Mark 14:36).

Chapter 4:8–20

Formerly the Gentile Galatians did not know God and served beings who by nature are not gods. Now they observe days, months, seasons and years and are returning to the weak and beggarly elements. Paul fears for them and appeals as a friend and a mother.

Chapter 4:21–31

Abraham had two sons, one by the slave woman (Hagar) and one by the free woman (Sarah). The first was born according to the flesh, the second through promise. Paul says these are two covenants: one from Mount Sinai, bearing children for slavery, corresponding to the present Jerusalem, and the other the Jerusalem above, who is free and our mother. He cites Isaiah 54:1 (rejoice, barren one) and Genesis 21:10 (cast out the slave woman). We, brothers, are children of promise, like Isaac. The conclusion is that we are not children of the slave woman but of the free.

The central teaching is that God's way of salvation is one throughout the Bible: by promise, received by faith. Abraham is the pattern. Paul argues that Abraham was justified before the law and before circumcision, so that he is the father of all who believe, Jew and Gentile alike (see also Romans 4). The law has a real but limited place in the history of salvation. It exposes transgression, restrains, and guards until Christ comes. Christian traditions differ on how the law still guides the believer. Lutherans stress its role in convicting of sin, the Reformed also teach a third use as a guide for the redeemed life, and Catholic teaching distinguishes the moral law, which remains, from the ceremonial and judicial laws, which have passed.

The second main teaching is the Trinitarian shape of redemption in 4:4-6: the Father sends the Son, and the Father sends the Spirit of the Son. Adoption describes the new status of believers, and the Spirit's cry of Abba confirms it. The Spirit and sonship are the inheritance promised to Abraham, in 3:14 and 4:6-7.

Third, 3:28 teaches that in Christ the ethnic, social and sexual divisions that mark the world no longer determine standing before God. The verse echoes baptismal language and anticipates 1 Corinthians 12:13 and Colossians 3:11. Christians agree that it teaches equal standing in Christ; they differ on whether it also speaks to roles in church and household.

Christ is the centre of the passage in at least four ways. He is the seed to whom the promise was made (3:16), the one in whom Abraham's blessing comes to the nations (3:14), the one who redeemed us from the curse of the law by becoming a curse (3:13), and the Son sent by God at the fullness of time (4:4). The use of Deuteronomy 21:23 is striking: the law pronounced a curse on a person hanged on a tree, and Paul sees in the crucifixion that Christ took the curse in the place of those under it. Acts 5:30 and 10:39 and 1 Peter 2:24 also use the word 'tree' for the cross.

The Old Testament connections are mostly promise and fulfilment. The promise to Abraham (Genesis 12:3) is fulfilled when the blessing reaches the Gentiles through Christ. Isaac, the child of promise, is in Paul's allegory a pattern for the children of promise; this is a type in Paul's own use, grounded in his statement in 4:28. 'Born of a woman, born under the law' (4:4) describes the incarnation as a true entry into human life under the law, and 'redeem' (exagorazō) is the language of buying out of slavery. The Jerusalem above (4:26) joins the promise of Isaiah 54 to the church, which is the new community of the Messiah.