Is the New Covenant for Israel Only..?

I was asked a question:

Q: Is the New Covenant only for Israel, or Israel Only (IO)? Isn't Israel the covenantal people of God? Isn't the New Covenant only for those redeemed from the Old Covenant? Isn't the heavenly kingdom nothing to do with people besides the covenant people?

Steven: At that time of the New Covenant, Jesus ushered it in, was to replace the Old Covenant. That happened when the temple and all its paraphernalia were destroyed COMPLETELY.

(side note: I wonder why people today wants to build a 3rd temple in Jerusalem. God destroyed the physical temple, so that He can live in us as a spiritual temple of God. How in the mind of God would He wants to stop dwelling in us, and go BACK to a physical temple.. It is just beyond my understanding.. Anyway.)

Jesus came to bring this message to Israel ONLY at that time. That was correct. Yet, in the love of God, Jesus did many miracles, healed, and proclaim the good news to the non-Jews. Jesus himself said that He was sent to speak only to the lost sheep of Israel (Mt 15:26).

Subsequently, after the New Covenant was in place, He brought this New Covenant to the whole world, Jews, Gentiles, everybody.

Ephesians 2:11-13 says: This New Covenant (this new system of God in us, and we in God/Jesus) is for ALL peoples. ALL peoples are now brought near to God. We now have hope and have God in this world. We have been brought near by the death of Jesus. We are now fellow citizens and called the household of God (Eph 2:19).

There are many more passages of verses to say that the New Covenant is not only for Israel but to ALL. It is no longer Israel Only (IO). It is Humanity Only (HO). It will take too much space to include them here.

Anyway, there are many other better writers like Micah Stephens, Jonathan Forgor, Daniel Leong who have expounded on this. So one can always read it with an open mind.