Christ is High Priest serving Israel under the Mosaic Covenant, which now fulfilled became the New Covenant.
The Church ("called out [ones]") is Israel also identified as the Great Congregation in the desert at the time of the Tabernacle, after having been called out of Egypt by the God of Abraham.
Israel being born-again in the first century became spiritual Israel until the destruction of their Temple by the Romans and Christ slowed building His Church, God gave Israel slumber, and the world entered the Times of the Gentiles until Daniel's seventieth week in which God turns His attention back to Israel, removes their blindness, sends two witnesses, and soon brings all human history to a close culminating with ALL Israel being saved, every Hebrew and seed of Abraham because God made covenant with Abraham and his seed and God will keep all remaining promises, even the giving to Israel all their Promised Land.
The error you and other Gentiles continue to make is to try to insert yourselves in the Hebrew Covenants, always using vague or misinterpreted NT passages to prove Gentiles in the Hebrew covenants when such interpretations would break Scripture, not really break it but the misinterpretations would contradict the Word of God in the Hebrew Scripture, for if there is no Old Testament precedence/prophecy then there is no New Testament reality.
Line upon line means something to God and to us, His born-again people.
And since there is no passage in the OT of God having covenant with Gentiles the only reasonable conclusion for presumed Gentiles who are born-again is that they are Abraham's seed and a mixed offspring of Jew-Gentiles somewhere in their family ancestry, just as Samaritans.
It is important to identify "Church" because you interpret it as being Gentile when it is not.