Isa 42, 46 show that Gentiles are included in the Covenant blessings, you blinded by the flesh and tradition,
Isa 42:1-6
Behold my servant, whom I uphold; mine elect, in whom my soul delighteth; I have put my spirit upon him: he shall bring forth judgment to the Gentiles.
2 He shall not cry, nor lift up, nor cause his voice to be heard in the street.
3 A bruised reed shall he not break, and the smoking flax shall he not quench: he shall bring forth judgment unto truth.
4 He shall not fail nor be discouraged, till he have set judgment in the earth: and the isles shall wait for his law.
5 Thus saith God the Lord, he that created the heavens, and stretched them out; he that spread forth the earth, and that which cometh out of it; he that giveth breath unto the people upon it, and spirit to them that walk therein:
6 I the Lord have called thee in righteousness, and will hold thine hand, and will keep thee, and give thee for a covenant of the people, for a light of the Gentiles;
Isa 49:6
6 And he said, It is a light thing that thou shouldest be my servant to raise up the tribes of Jacob, and to restore the preserved of Israel: I will also give thee for a light to the Gentiles, that thou mayest be my salvation unto the end of the earth.
That was the mystery, Gentiles and Jews together partake of the same Gospel promise to israel Eph 3 6
6 That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel:
Also "light to the gentiles" denotes regeneration, theyll be regenerated to see the Light of the Gospel