Paul was not trained in a modern seminary to read Scripture. As a man of his day, he read Scripture like the rabbis he had heard in the synagogue or studied under in the academy. Often the ways he reads and interprets Scripture seem odd to us. Still they were the strategies his teachers and other biblical writers were using at the time.
Midrash is a term used to refer to how Jewish teachers approached and explained the biblical texts. It begins with a healthy respect for the Scriptures as divinely inspired, as God’s Word to the world. Yet as God’s Word the books of the Bible must do more than tell about what happened back then, they must be read against our current questions, crises and moments. Whenever you hear a sermon about timeless truths or life principles from the Bible, the teacher is engaging in midrash. One way to think of it is to say these ancient texts also speak to modern problems.
For Paul there are many ways of realizing the significance of the Scriptures in his day. The allegory of Sarah and Hagar (Gal 4:21-31) is one of them. Paul offers a figural reading of Abraham’s two sons, one born to Hagar, the other to Sarah, his wife. For him, these two women serve as representative figures of the current problem Paul is addressing in Galatians. Now, this does not mean that Paul discounted the literal, historical meaning—a memorable story of how God had been working out his promises to Abraham and his family—he just sees in the conflict within Abraham’s family a correspondence between the conflict that he was trying to work out among believing Jews and Gentiles in his day.
Like Hillel, one of the great rabbis of his day, Paul often made use of catch words to link one text to another so that they become mutually interpreting. You might call this “stringing pearls.” In Gal 3:6-9 Paul mixes his own commentary (midrash) with Scripture:
Text (Gen 15:6) Abraham put faith in God and it was reckoned to him as righteousness
Comment Those who put faith (in Jesus) are the sons of Abraham
Comment Scripture foretold that God would makethe Gentiles right by faith
Text (Gen 12:3) in you, Abraham, all the Gentiles would be blessed
Comment Those who put faith (in Jesus) are blessed with Abraham who had faith
The story of Abraham provides Paul with a Scriptural image for how to address the predicament in Galatia. Abraham’s “faith” became the occasion for how the patriarch was reckoned by God as “right/righteous”; but what was true for Abraham is also true for all the sons of Abraham, defined by Paul as those, including the Gentiles, who put faith in Jesus. As Paul continued to think through the story of Abraham, his mind shot back to the initial promise itself where God promised Abraham that he and his kin would become a blessing universally to all the nations/Gentiles. These keywords within Abraham’s story (faith, right/righteous, blessing, Gentiles) became the pearls by which the apostle could string together his Scriptures to include this new chapter, the climactic chapter of God’s story in the world.