I am aware that there are many people who claim that God was only concerned with the Israelite people establishing his everlasting Kingdom with them alone. And I recognize that many of the arguments put forth to substantiate this type of position have some validity. However, I do question that singular conclusion when I read passages like the following:
Luk 2:25-32: “And, behold, there was a man in Jerusalem, whose name was Simeon; and the same man was just and devout, waiting for the consolation of Israel: and the Holy Ghost was upon him. And it was revealed unto him by the Holy Ghost, that he should not see death, before he had seen the Lord’s Christ. And he came by the Spirit into the temple: and when the parents brought in the child Jesus, to do for him after the custom of the law, Then took he him up in his arms, and blessed God, and said, Lord, now lettest thou thy servant depart in peace, according to thy word: For mine eyes have seen thy salvation, Which thou hast prepared before the face of all people; A light to lighten the nations, AND the glory of thy people Israel.”
In this passage, I see a distinction between the people of Israel and the rest of the nations and that the Messiah would be a light for BOTH.
A famous passage in Isaiah reads:
Isa 49:6: “And he (YHWH) 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 nations, that thou mayest be my salvation unto the end of the earth.”
Coupling these two prophetic thoughts together which span a period of time over 600 years, I think it becomes plain that God’s plan for his kingdom is that the Messiah would rule and reign over Jacob, Israel, AND the nations in a kingdom that would never end.