Throughout the Old Testament, Abraham, Isaac, and Jacob are described as the fathers of Israel, and conversely Israel is portrayed as the descendants or children of Abraham. As Abraham’s children, the Jews believed they were to inherit the promise made to Abraham. This promise was passed down through Isaac to Jacob. Those not born of Abraham, Isaac, and Jacob were not of the promise. They were not of “the family.” Furthermore, over the centuries it had become ingrained in Jewish thought that observance of the Law was what kept Israel as “Israel.” It kept them from “going native” in the world. Losing the Law and the traditions would dissolve their distinctiveness and they would lose the inheritance promised to them.
Yet the promise to Abraham was that “all peoples on earth” would be blessed through him. In our analysis of the parable of the Great Banquet we saw how the grand vision of God bringing all peoples of the earth into the household had morphed into a vision where Israel is saved and everyone else destroyed.
Jesus had taken the fictive family metaphor of his day and transformed it into a vision of a household with God as the paterfamilias actively seeking out and bringing in both law-breaking sinners and law-keeping sinners. The family metaphor was ready made to be a unifying metaphor for a Jewish audience but Paul was now in “the highways and hedges” of Jesus’ Great Banquet metaphor, bringing in Gentiles. Family is precisely the metaphor the Jews have relied on to exclude the Gentiles. Paul must metaphorically find a way for Jew and Gentile to be of the same family. How would he do it?
1 What then are we to say was gained by Abraham, our ancestor according to the flesh? 2 For if Abraham was justified by works, he has something to boast about, but not before God. 3 For what does the scripture say? "Abraham believed God, and it was reckoned to him as righteousness." 4 Now to one who works, wages are not reckoned as a gift but as something due. 5 But to one who without works trusts him who justifies the ungodly, such faith is reckoned as righteousness. 6 So also David speaks of the blessedness of those to whom God reckons righteousness apart from works:
7 "Blessed are those whose iniquities are forgiven,
and whose sins are covered;
8 blessed is the one against whom the Lord will not reckon sin."
9 Is this blessedness, then, pronounced only on the circumcised, or also on the uncircumcised? We say, "Faith was reckoned to Abraham as righteousness." 10 How then was it reckoned to him? Was it before or after he had been circumcised? It was not after, but before he was circumcised. 11 He received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised. The purpose was to make him the ancestor of all who believe without being circumcised and who thus have righteousness reckoned to them, 12 and likewise the ancestor of the circumcised who are not only circumcised but who also follow the example of the faith that our ancestor Abraham had before he was circumcised.
13 For the promise that he would inherit the world did not come to Abraham or to his descendants through the law but through the righteousness of faith. 14 If it is the adherents of the law who are to be the heirs, faith is null and the promise is void. 15 For the law brings wrath; but where there is no law, neither is there violation.
16 For this reason it depends on faith, in order that the promise may rest on grace and be guaranteed to all his descendants, not only to the adherents of the law but also to those who share the faith of Abraham (for he is the father of all of us, 17 as it is written, "I have made you the father of many nations") -- in the presence of the God in whom he believed, who gives life to the dead and calls into existence the things that do not exist. 18 Hoping against hope, he believed that he would become "the father of many nations," according to what was said, "So numerous shall your descendants be."
Galatians 3:6-9, 15-18
6 Just as Abraham "believed God, and it was reckoned to him as righteousness," 7 so, you see, those who believe are the descendants of Abraham. 8 And the scripture, foreseeing that God would justify the Gentiles by faith, declared the gospel beforehand to Abraham, saying, "All the Gentiles shall be blessed in you." 9 For this reason, those who believe are blessed with Abraham who believed. …
… 15 Brothers and sisters, I give an example from daily life: once a person's will has been ratified, no one adds to it or annuls it. 16 Now the promises were made to Abraham and to his offspring; it does not say, "And to offsprings," as of many; but it says, "And to your offspring," that is, to one person, who is Christ. 17 My point is this: the law, which came four hundred thirty years later, does not annul a covenant previously ratified by God, so as to nullify the promise. 18 For if the inheritance comes from the law, it no longer comes from the promise; but God granted it to Abraham through the promise.
Paul leaves the idea of the Jewish family in place but casts a vision of the Jewish family as unit of a larger family. Membership in this larger fictive family is no longer based on biology and preserving tradition. Membership is based on exercising faith as Abraham did, making Jews and Gentiles brothers and sisters of each other in the Household of God.