“The promise of the Spirit through faith”
That the blessing of Abraham might come upon the Gentiles through Jesus Christ, and that we might receive the promise of the Spirit through faith.
Paul here, as elsewhere, spiritualizes and allegorizes the notion of kinship. If for rabbinic Jews the crucial signifier is actual, physical descent from Abraham, for Paul, it is descent from Abraham according to the spirit, which is constituted by entry into the faith community of Christ. He equates the promise made to Abraham that Sarah would bear Isaac to Abraham's spiritual paternity of Jesus, “the seed” to whom the promise was made, and through Jesus, the seed of all who believe. Thus the exegetical notion that the blessing is for the descendants of Abraham by the “promise” and not to those who are his descendants “by the flesh” is fulfilled in time by God through the sending of the Messianic seed through which the promise was made. The fulfillment of the promise is, however, through the participation of the people in the spirit which has been offered them by Christ's crucifixion. Entering into the spirit, by participating themselves in the experience and commitment of the crucifixion and resurrection, constitutes acceptance of the gift and thus entering into the descent by the promise, the type of which was the birth of Isaac through the promise and not by the natural carnal means.[18] Indeed, it is not so much Abraham who is the type of Christ but Isaac. God offers adoption as spiritual children through the sacrifice of his son, but people either accept it or reject it. They accept it by allowing the gifts of the spirit into their hearts. If they reject it by going back to the works of the Law, implying thereby that only physical descent or physical adoption into the Jewish family saves, then Christ died on the cross in vain. As Ferdinand Christian Baur put it so precisely at the end of the nineteenth century, “According to the [Jerusalem apostles], it is in vain to be a Christian without being a Jew also. According to [Paul], it is in vain to be a Christian if, as a Christian, one chooses to be a Jew as well” (Baur 1875, 57).
In Galatians Paul is supporting the connection between the allegorical theory of the Law and christology. The two midrashim together provide the argument. The Law itself has already informed us of its own dual nature by telling us that anyone who remains with the physical level of “doing the Law” has not fulfilled the Law. This is then followed by the midrashic argument that anyone who merely does the Law is not living by faith, which alone justifies, and finally that Christ through his crucifixion has revealed the true meaning of the Law, namely, that its material signifier is to be replaced by its spiritual signified. In the next section Paul will turn to the third aspect of the triad, the question of physical descent and genealogy, which he will also read in accord with the allegorical structure.