There is a borderline case here of reducing the Lordship of Jesus Christ by not making a sharp distinction between the OT and the NT. The New Testament witness of the Apostles is unique to anything that has come before, or else Paul's conversion away from Judaism is meaningless or has no validity. And, what Paul declares in Galatians isn't that important, perhaps, according to those who find a problem with making these sharp distinctions. M. Luther had seen what was going on in Galatians and projected its meaning and substance to what the Papacy represented at that time. The same could be said of our modern situation in Christianity in relation to biblical hermeneutics or how we believe people get saved from sin, death and the devil.
Paul makes clear that we have the same faith as Abraham. What he rejects is the mutation/perversion of the Old Testament's message from pointing to coming Savior (Gospel) to a Law-based, save yourself by works thing.
Again yes we do have the same faith as Abraham and Abraham is our common ancestor in terms of faith per Genesis 12. However Abraham (or Abram) received this promise before he was circumcised, before he could claim a national identity, ie. Judaism. Galatians and Romans are clear about that. Again God's word here and God's word there. But we have to make distinctions as to how law and Gospel are applied.
Abram and his offspring (through Sarai) are God's people because God said so. Not because of circumcision or obedience to the law. Walter Brueggemann argues that circumcision and obedience to the law were never a means of salvation. "Works righteousness has no place with the covenant people." They were always God's people because God said so. Circumcision and obedience were to let the rest of the world know that they were God's people. They were to be different from the people around them.
My point is that God chose Abram prior to any defining marks of ethnic identity. God chooses his people not based on “people-hood” but based on God’s choice of individuals regardless of who each one is. Circumcision defined a stream of ethnic people. God’s people are those individuals within Judaism as well as any “Gentile” person whom God calls. It’s the faithful person before God’s face. Not the people in general or certain persons in general.
Biblically, ethnicity began with the sons of Noah. Shem is the father of the semites. His great-grandson, Eber, is where the name "Hebrews" comes from. Five generations later came Abram, Nahor, and Haran. Identities were created by genealogies.
Circumcision was practiced by many ancient near eastern people. Jeremiah 9:25-26 lists Egyptians, Judeans, Edomites, Ammonites, Moabites, and other desert dwellers as people who were physically circumcised.
"The Greek historian Herodotus, writing in the 5th century BCE, contended that circumcision originated with the Egyptians; archaeological data support the presence of the practice among the Egyptians from at least the 23rd cent. BCE. Yet, other archaeological evidence shows Syrian warriors circumcised from about 3000 BCE; thus, it may be that the practice began with Northwest Semites and extended, in turn, to Egypt." (
The New Interpreter's Dictionary of the Bible, volume 1, "Circumcision," p. 668).
