Lets start here, there is no such thing as a New Covenant Israel, that is a misreading/understanding of the bible. Israel is Israel, Gal. 3 is saying just the opposite of what people who think in this manner, ascribe it to mean. Its saying to the Galatians, HEY, STOP trying to be Jews in order to make it to heaven via keeping the Sabbath etc. etc. Then he cites how the Law was never the covenant, it was added 430 years AFTER the Promise !! Then Paul tells them, there is neither Jew nor Greek (Gentile) slave nor freeman, male nor female (THINK).......Are there still males and females? This ought to ring an alarm bell. Paul's whole point is God doesn't see us in CLASSES, He sees us not as Male and Females, not as Jews and Greeks so STOP trying to keep the law like he Jews in order o make it to Heaven, he's not saying there are now no Jews and we are ALL ONE any more than he's saying we are all transexuals (one gender) now.
NOW knowing this REREAD the whole chapter, its obvious what he's saying, O Foolish Galatians who has deceived you that arising in THE FAITH, you are now trying to please God via THE FLESH (keeping the Laws like the Jews). Then he goes on and on how THE PROMISE is the real Covenant, not THE LAW, and says once the Law was just a schoolmaster to bring us unto Christ Jesus THE PROMISE, so the whole chapter is Paul rebuking te Galatians for thinking they had to be "Jew like" in order to make it to heaven, Paul this says NO............be yourselves, God accepts both Jews AND Greeks, Males AND Females, Slaves AND Freemen, all via FAITH ALONE. He's is NEVER, NEVER, EVER saying we are all ONE Nation now. The Church still has a specific calling, and it has bot Jews and Gentiles, but mostly Gentiles, the Jews will mostly repent during the 70th week AFTER the Rapture, thus when Jesus sets up his 1000 year reign in Jerusalem there will be about 5 million Jewish people, Jesus thus will have a Jewish peoples dwelling in Israel to rule with him in the "Kingdom Age".
Satan is very sneaky, and a lying deceiver.
This is VERY EASY to understand, the code is the Old Testament.
Gen. 37:9 And he dreamed yet another dream, and told it his brethren, and said, Behold, I have dreamed a dream more; and, behold, the sun and the moon and the eleven stars made obeisance to me.
The Sun was Jacob, the Moon was Rachel, the 11 Stars his brother and he was the 12th Star so Jacob, Rachel and their kids make up Israel.
All the whole the "SIGN is a Horoscope Sign" was always a joke of a theory.