Jan Lambrecht, «Abraham and His Offspring. A Comparison of Galatians 5,1 with 3,13», Vol. 80 (1999) 525-536
Just as after the Abraham passage of 3,6-12 Christ is mentioned in 3,13 quite unexpectedly, so also after 4,21-31, Pauls so-called allegory which deals with the wives and sons of Abraham, the sudden statement about Christ in 5,1 cannot but surprise the reader. Although the word order differs, both vocabulary and content of parts of 3,13a and 5,1a are identical or at least similar. Abrahams faith was already, by way of anticipation, Christian faith. Moreover, "those of faith" in 3,7 and 9 implicitly are believers in Christ. This also applies to 4,26. The children of "the Jerusalem above" are free because they belong to Christ, even if in v. 26 this is not (yet) explicitly stated. Therefore, a seemingly brusque transition from the Abraham text or the allegory to Christ should not disturb the reader too much.
verses the insight is forced upon the reader that the parallel between Abraham and the Gentiles is in the end not so simple. The sequence "faith-blessing" may have been possible for Abraham. Without the intervention of Christ, however, it remains impossible for his children. Previously there was blessing thanks to faith; now Christ must first redeem humanity from the curse of sin.
Yet it should be realized that this qualification is not completely correct, since for Paul redemption by Christ is certainly more than a first step, more than as it were a necessary condition before justification can take place. Redemption by Christ is the justification itself. The needed faith is specifically faith in Christ. In Christ Jesus the blessing of Abraham comes upon the Gentiles (v. 14a) and through faith in Christ all Christians Gentiles as well as Jews receive the promise of the Spirit (v. 14b). One must, however, nuance these considerations once more. Strictly speaking, Abrahams faith too was not without a "christological" content. For he believed in Gods promise which attained its realization and fulfillment precisely in Jesus Christ. This means that Abrahams faith and that of the Galatians may not be radically distinguished. Just as his children, Abraham too had to believe in Gods new initiative of salvation in order to be justified. For Abraham that initiative was still a promise; for the Galatians it has become reality.
II. Like Isaac, Children of the Promise
Galatians 3 is full of Old Testament quotations and references. It is understandable that Paul, writing this letter to a community consisting for the most part of Gentile Christians, introduces "a human example" in 3,15: "no one annuls even a mans will, or adds to it, once it has been ratified". But immediately afterwards, he resumes his reasoning with data taken from scripture. In 4,1-2 the profane humane reality, well known to the Galatians, is once more brought forward: "I mean that the heir, as long as he is a child, is no better than a slave, though he is the owner of all the estate; but he is under guardians and trustees until the date set by the father". The application of this is worked out in 4,3-7. Pauls exclamation "how can you turn back again ..." is the center of 4,8-11, a brief passage in which he also expresses his fear: "I am afraid I have labored over you in vain" (v. 11). Then there follows in 4,12-20 a personal pleading in which Paul reminds the Galatians of their mutual loving relations. He also accuses his opponents: "they make much of you, but for no good purpose" (v. 17). This last pericope ends on a pathetic note: "I could wish to be present with you now and to change my tone, for I am perplexed about you" (v. 20).
In Gal 4,21-315 Paul returns to Scripture: "Tell me, you who desire to be under law, do you not hear the law?" "Law" is evidently used here