After all the pulling and straining at scripture, it boils down to a question of whether God loves and cares for all His creation, or does God mostly care for Israel? If you only go by scripture, it tells us that God sees all humans as the same. If God loves and guides Israel, then God wants to guide and love all people the same.
Scripture often speaks of directing that scripture to Israel, but there is not one time it tells us "Israel only". In fact scripture goes out of its way, in verse after verse, to explain God means for it to be to anyone who accepts Him.
To make this clear to us, there are passages saying we are of Abraham's seed if we love Him. And YET people reject scripture based on it isn't directed to them!!!
God has one covenant people, Israel. If you are not born of Israel, and you love God, you are adopted into Israel's promises, and you and your posterity, who chose to love God, become Israel.
Exodus 12 (ESV)
37 And the people of Israel journeyed from Rameses to Succoth, about six hundred thousand men on foot, besides women and children.
38 A mixed multitude also went up with them, and very much livestock, both flocks and herds.
Ruth 1 (ESV)
16 But Ruth said, "Do not urge me to leave you or to return from following you. For where you go I will go, and where you lodge I will lodge. Your people shall be my people, and your God my God.
Hosea 1 (ESV)
4 And the Lord said to him, "Call his name Jezreel, for in just a little while I will punish the house of Jehu for the blood of Jezreel, and I will put an end to the kingdom of the house of Israel.
5 And on that day I will break the bow of Israel in the Valley of Jezreel."
6 She conceived again and bore a daughter. And the Lord said to him, "Call her name No Mercy, for I will no more have mercy on the house of Israel, to forgive them at all.
7 But I will have mercy on the house of Judah, and I will save them by the Lord their God. I will not save them by bow or by sword or by war or by horses or by horsemen."
8 When she had weaned No Mercy, she conceived and bore a son.
9 And the Lord said, "Call his name Not My People, for you are not my people, and I am not your God."
10 Yet the number of the children of Israel shall be like the sand of the sea, which cannot be measured or numbered. And in the place where it was said to them, "You are not my people," it shall be said to them, "Children of the living God."
John 11 (ESV)
47 So the chief priests and the Pharisees gathered the council and said, "What are we to do? For this man performs many signs.
48 If we let him go on like this, everyone will believe in him, and the Romans will come and take away both our place and our nation."
49 But one of them, Caiaphas, who was high priest that year, said to them, "You know nothing at all.
50 Nor do you understand that it is better for you that one man should die for the people, not that the whole nation should perish."
51 He did not say this of his own accord, but being high priest that year he prophesied that Jesus would die for the nation,
52 and not for the nation only, but also to gather into one the children of God who are scattered abroad.
53 So from that day on they made plans to put him to death.
54 Jesus therefore no longer walked openly among the Jews, but went from there to the region near the wilderness, to a town called Ephraim, and there he stayed with the disciples.
Romans 11 (ESV)
26 And in this way all Israel will be saved, as it is written, "The Deliverer will come from Zion, he will banish ungodliness from Jacob";
27 "and this will be my covenant with them when I take away their sins."
Acts 1 (ESV)
6 So when they had come together, they asked him, "Lord, will you at this time restore the kingdom to Israel?"
7 He said to them, "It is not for you to know times or seasons that the Father has fixed by his own authority.
8 But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth."
Revelation 21 (ESV)
9 ..."Come, I will show you the Bride, the wife of the Lamb."
10 And he carried me away in the Spirit to a great, high mountain, and showed me the holy city Jerusalem coming down out of heaven from God,
12 It had a great, high wall, with twelve gates, and at the gates twelve angels, and on the gates
the names of the twelve tribes of the sons of Israel were inscribed—
13 on the east three gates, on the north three gates, on the south three gates, and on the west three gates.
14 And the wall of the city had twelve foundations, and on them were the twelve names of the twelve apostles of the Lamb.
24 By its light will the nations walk, and the kings of the earth will bring their glory into it,
25 and its gates will never be shut by day—and there will be no night there.
26 They will bring into it the glory and the honor of the nations.
27 But nothing unclean will ever enter it, nor anyone who does what is detestable or false, but only those who are written in the Lamb's book of life.