The children of the promise are Christian.
When Paul was discussing the fact that the promise does not follow down every bloodline, what do you think he was illustrating?
It was God's sovereign will that the PROMISE will follow from a strict, chosen, Jewish, bloodline.
If you do not understand the bloodline please read Luke 3:23.
When Paul mentions in Rom 2 that an outward Jew is not a Jew, what do you think he was talking about?
Jewish conversion to Jesus Christ and the sanctification that the Holy Spirit endows.
Look at Rom 9 again. In Rom 9:6 he states "not all of Israel are Israel".
Correct but Paul is still tracing the bloodline of the chosen Jewish lineage. May I say that many in Israel are of Israel.
In Rom 9:7 he gives an example about how the identity is not passed by bloodline alone.
Read the genealogy given in Luke 3. There is a very long list of Jewish names given in that bloodline, God chose that specific bloodline for a purpose.
In Rom 9:8 he states "that is to say those of bloodline are not children of God, but those of the promise are counted for the heirs".
True but Sarah will have a son.
In Rom 9:17 he explains that God will sometimes raise people up to think they are so great for the purpose of making an example of them, to demonstrate His power and His mercy. This would mean it would be completely consistent with His designs to raise antiChrist Jews into high power solely for the purpose of making an example of them.
God bound everyone over to disobedience so that He can have mercy on them all. (Romans 11:32)
If you fixate on cherry-picked words, it is easy to miss the nuance of what he is talking about. He isn't saying that all descendants of Isaac are chosen/elect/etc. He is stating that the promised are only a subset of descendants and not elect on the basis of merely bloodline. If you look deeper into scripture you will find that it is only those in Christ that are heirs to the promise. Not all of Israel are Israel, this exclusion is not limited to nonIsaac descendants.
Your trying to undermine the genealogy of the Christ, the promised one.
You also cannot accept that God chose the Jews, Jerusalem, and Israel.
I do not fixate, I cover all of the letter to the Romans.