God said he would make Ishamel the father over 12 tribes. Isaac was the father of the 12 tribes of Israel. If Jerusalem and the Jews are identified with Ishamel as they do appear to be, who are the Jews descended from Isaac? I hope my confusion is clear and would appreciate your thoughts! Thank you!

I hope I understand your question. The Bible says that Ishmael was to beget 12 princes and God was going to make him a great nation (Gen. 17:20). We find the fulfillment of this in Gen. 25:12-16. This is purely a physical or natural fulfillment But Paul in Galatians 4 is not really speaking of Ishmael and his descendents or a natural fulfillment. He never mentions Ishmael by name but his mother Hagar who according to the allegory is Mt. Sinai in Arabia.

What would a Jew of Paul's time think of when Mt. Sinai is mentioned. It is the place where God expressed his "conditional" covenant to Moses and Moses to the people, ‘Ye have seen what I did unto the Egyptians, and how I bore you on eagles’ wings and brought you unto Myself. Now therefore, if ye will obey My voice indeed and keep My covenant, then ye shall be a peculiar treasure unto Me above all people; for all the earth is Mine. And ye shall be unto Me a kingdom of priests and a holy nation.’ These are the words which thou shalt speak unto the children of Israel." Ex. 19:4-6.

It is also the place where God wrote his commandments on tablets of stone and even before Moses came down off the mountain the people had broken the covenant making a calf of gold and worshipping it. Had it not been for Moses’ intercession God would have destroyed them all at that time and started over (still fulfilling the original Abrahamic covenant as Moses was a direct descendant of Abraham).

The terms of that covenant were never again ratified with that people. From that time on Israel, the physical nation committed disobedience upon disobedience. Without going into a long explanation of the original blood covenant and then the inferior substitute covenant God made with his people, they became the children of bondage in the allegory. God destroyed them in 70 A.D.

So what about Isaac and his descendents. Well Paul says is that this is an allegory of two covenants. Hagar is Mt. Sinai which is Jerusalem as it was in Paul's day. Read Matthew 23 to see what Jesus thought of the Jewish legal system of the time and what He was going to do with them of that generation.

But what does Paul say about Isaac. "Now we, brethren, as Isaac was, are the children of promise." (Gal 4:28) We (those in Christ and part of the Kingdom of God, or the Kingdom of heaven) are not bound to the law (Mt. Sinai, Hagar, the old Jerusalem). We are of the new covenant, the everlasting covenant. We are not bound, we are free. We are not 12 tribes but we are from all the nations of the earth including Jews who have come to know Christ through His blood sacrifice, including Arabs who have come to know Christ through His blood sacrifice, etc., but only those who have come to know Jesus through His blood sacrifice, His resurrection and His ascension. Hagar and her son Ishmael were physical realities of the Old Testament, we along with Isaac are spiritual realities of the new for first comes the physical (natural) and then the spiritual. (1 Cor. 15:46). It is through us (members of the Kingdom) that God has fulfilled and continues to fulfill his original everlasting Abrahamic covenant.