Summary: Gal. 4:21-5:1 is a great use of an analogy by Paul to show the difference between the Mosiac Covenant and the Covenant brought by Jesus Christ.
In this text Paul continues to contrast grace and law, faith and works. Under the guidance of the Holy Spirit he employs an Old Testament story as an analogy, which serves not so much as an argument as an illustration.
Paul here doesn’t give us a explanation of why, after the powerful and irrefutable arguments he has already given, to know chose allegory as a means of further persuasion.
Allegory as such is a shaky and dangerous means of interpretation. Because allegory does not need to be based on fact, it is limited only by an interpreter’s imagination and is easily influenced by his personal predispositions. It frequently leads to biased and often bizarre conclusions.
The ancient rabbis regularly used an allegorical approach to interpret Scripture, often claiming to discover amazing, hidden, and extremely fanciful “truths” that supposedly lay behind the ordinary meaning of the words of a text. During the last several centuries before Christ, Jewish scholars in Alexandria developed a system of scriptural allegory that strongly influenced not only Judaism but also Roman Catholicism until the time of the Protestant Reformation. For example, the Euphrates River was seen as the out flowing of good manners. The journey of Abraham from Ur to the Promised Land pictured a stoic philosopher who left his sensual understandings and came to his spiritual senses.
Allegory is a Pandora’s Box that ignores the literal, historical meaning of Scripture and opens biblical interpretation to every extreme. Because of man’s infiniteness and fallenness, it inevitably leads to arbitrariness, absurdity, and futility.
The Holy Spirit here directs Paul to use analogy on this occasion in order to show the Judaizers that God’s plan of redemption has always been by grace. As Paul develops the analogy, he first gives its historical background, then its divine interpretation, and finally its personal application.
I. The Historical Background (vv. 22-23)
• Paul first reminds his readers of their forefather Abraham, beginning of the Hebrew race.
o It was in their racial descent from him that most Jews of Paul’s day placed their trust for salvation.
o If I am related to Abraham, then I am saved, they believed.
• Paul’s first historical reminder to them about Abraham was that he had two sons.
o The sons were distinct in a number of ways: they had different mothers
o One was a bondwoman (Hagar) who bore Ishmael.
o One was a free woman (Sarah) who bore Isaac.
• Throughout Paul’s analogy, all distinctions between the two sons are based on the fact that they have different mothers, not on the fact that they had a common father.
o The heritage of the line through one mother is lostness and bondage
o The heritage of the line through the other mother is salvation and freedom.
• Paul’s second historical reminder was that the son by the bondwoman was born according to the flesh, and the son by the free woman through the promise.