Well consider how he has been with his people all throughout the bible, he never gave up on them and would constantly promise them things and bible prophecy like history tends to repeat itself.In the prophets, the restoration, the outpouring and the outreach to the nations are all together. That's what Peter was showing by quoting Joel 2 in Acts 2. I do not know a NT passage that details a restored race-nation; I know many that say the living temple now is 'one people together in Christ.'
When Israel returned to it's land in 1948 this was one of the most massive prophecies fulfilled in history aside from Jesus
But this is bigger than jews and gentiles Israel and the church it is about the kingdom his kingdom grafts all together he was the original parent and loves his children no matter what race or ethic groups the bloodlines were dispersed all the way back in the old testament but the bloodline of Christ is the one that is going to bring all people of every race and generation to his throne in unity.
Israel is the prodigal son.