I'm still a bit fuzzy on what you are saying in regards to that passage. You say that it applies to the physical descendants - but you also agree that it applies to the gentile converts.
If the "house of Israel" and the "house of Judah" includes gentile converts - then physical lineage is not the deciding factor in who the new covenant applies to. Correct?
You said that not all of the physical descendants of Abraham will be counted as true sons. In what circumstances will some of Abraham's children not be counted as true sons?
Was is possible that some of Abraham's physical descendants living in Israel were not "true sons" when Jeremiah gave this prophecy?
One of the main verse in Galatians I would like you to address is 4:30 where it says the sons of Hagar (Jews who continue to cling to the Law instead of Christ) will not share in the inheritance.
Isn't this a clear teaching that some of Abraham, Isaac, and Jacob's physical descendants won't be counted as true sons?
Rom 11:2 God hath not cast away his people which he foreknew. Wot ye not what the scripture saith of Elias? how he maketh intercession to God against Israel, saying,
Rom 11:3 Lord, they have killed thy prophets, and digged down thine altars; and I am left alone, and they seek my life.
Rom 11:4 But what saith the answer of God unto him? I have reserved to myself seven thousand men, who have not bowed the knee to the image of Baal.
Rom 11:5 Even so then at this present time also there is a remnant according to the election of grace.
Rom 11:6 And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work.
Rom 11:7 What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded
LA