Protestant biblical theology requires a rigorous historical as well as grammatical exegetical approach and a disciplined typological method.
– J. I. Packer
The greatest crisis in the early life of the apostolic church was clearly the challenge to the gospel of free grace represented by the Judaizers, the controversy which necessitated the first ecumenical council at Jerusalem (Acts 15:1-3). Paul’s epistle to the Galatians represents the most urgent and passionate defense of the gospel of grace in all the New Testament. Indeed, the stakes could not have been higher for the infant church in that controversy.
Paul is so sobered by the threat of the Judaized gospel, which he calls no gospel (Gal 1:7), that he pronounces a curse (Gal 1:8) and an imprecation upon his opponents (Gal 5:12).
Now it is instructive that when the issue was so decisively drawn with his legalist opponents, Paul, at the climax of his argument, appealed to an allegory to refute the gainsayers of grace (Gal 4:24). It seems a fair question to ask our fellow Protestants whether, without the sanction of Holy Scripture, we would ever find the claim that Sarah and Hagar “are two covenants” persuasive. Would it be self-evident to us, as it apparently was to Paul and the Galatians, that these two women appearing in early Genesis dispositively anticipated the covenants of promise and works? Would Protestant scholarship today be capable of demonstrating, apart from Paul, the biblical theological bicovenantal theme of flesh and promise as represented by Hagar and Sarah (Gen 16:5 and 21:2, cf. Gal 4:24), Sinai and Zion (Exod 19:8 and Psa 48:2, cf. Gal 4:24-27), barren Jerusalem and fertile Zion (Isa 49:20-21 and 54:1, cf. Gal 4:27), and the Jerusalem of the second temple and the Jerusalem above (Gal 4:25-26)?
Let’s consider the first and most critical part of the question we have raised as to how Paul would have made the identification of Hagar with Sinai, and how such a comparison is defensible within the bounds of the historical-grammatical method. Perhaps the most striking grammatical similarity between the accounts of Hagar and Israel at Sinai is the use of the rare word tsachaq (to mock), found in both accounts (Gen 21:6 and Exod 32:6). The identifying gesture of Ishmael, the son of the bondwoman, was to “mock” Isaac, the son of Sarah who had received the promise. This “mocking” of Ishmael (Gen 21:6) is what makes Moses’ use of the same word so significant when he describes the idolatry of the sons of Israel at Sinai who, like Ishmael, rose up to “mock” (Exod 32:6). Just as Paul would afterwards announce the doctrine that not all Israel is Israel (Rom 9:6), so Moses anticipates the same remnant doctrine when he charges the rebels at Sinai with rehearsing the action of Ishmael (Exod 32:6).
Now with respect to the Mosaic account of the similarity of Ishmael to Israel at Sinai, both Ishmael and disobedient Israel can boast in Abrahamic paternity. Both are circumcised (Gen 17:23; Josh 5:4-5). Yet idolatrous Israel is in jeopardy of not inheriting the blessing due to unbelief like that of Ishmael. By the use of a highly significant and rare word, Moses is inviting us to compare the two narratives that juxtapose faithless Israel and Ishmael. This Mosaic equation of Ishmael and idolatrous Israel at Sinai makes Paul’s argument against the Judaizers so probative, for like Ishmael, they too claimed both Abrahamic paternity and covenant circumcision. So with respect to the correspondence between the son of Hagar and Israel at Sinai, we observe a case of verbal concordance and structured similarity that suggests an intentional mirroring (or poetic comparison) of the two accounts by the sacred writer.
A further clue to the interpretive framework of the Apostle Paul is the syncritical juxtaposition of two women, a common trope both in the biblical texts and the literature of both the Jewish and the Hellenistic Galatians. This figure of speech presents two women in order to contrast two ethical possibilities. The book of Proverbs, for example, which is highly exhortative, opens with a warning about the immoral woman (Prov 2:16-19) and ends with an admonition to marry the woman of virtue (Prov 31:10-31). The same admonitory charge is evident in Paul’s instruction to cast out the bondwoman of legalism (Gal 4:30) and adhere to the woman of promise (Gal 4:31) as well as the Johannine charge to exercise wisdom in discerning the different destinies presented by Lady Babylon (Rev 17:5-9) and Lady Zion (Rev 21:1-2). To understand Paul’s allegory fully requires a familiarity not only with the Bible but with the literature of the original recipients, at least if we are to take seriously the historical component of historical-grammatical exegesis. It is in this area especially that we see great hope as Protestants become increasingly attuned to the contribution of classical and Septuagintal study to New Testament exegesis, along with the already quite well established recognition of the value of the study of second temple Judaism.
In sum, the poetics of a Protestant biblical theology requires a rigorous historical as well as grammatical exegetical approach and a disciplined typological method. J. I. Packer has clearly defined the approach we are advocating:
Biblical theology is the umbrella-name for those disciplines that explore the unity of the Bible, delving into the contents of the books, showing the links between them, and pointing to the ongoing flow of the revelatory and redemptive process that reached its climax in Jesus Christ. Historical exegesis, which explores what the text meant and implied for its original readership, is one of these disciplines. Typology, which looks into the Old Testament patterns of divine action, agency, and instruction that found final fulfillment in Christ, is another.