The gospel preached to Gentiles should somehow make unbelieving Jews jealous
When I read these words, I wondered if much of our preaching in the evangelical world would make Jews that do not believe in Jesus jealous.
Granted Judaism has changed since the days of Paul, but the joy and sadness of Paul seems to be that all the rich covenant promises that God made to Abraham and through Moses to the people of Israel, (e.g. that they would be a royal priesthood and holy nation, God's own treasured possession in all the earth, that God's justice would be with them and that they would inherit the earth, etc.) are now made available to the Gentiles because Israel has rejected the gospel of God temporarily. Paul rejoices because the Gentiles get to inherit the promises, but he is sad because the people who should have inherited them have rejected Christ.
Nevertheless, because of God's steadfast love to Abraham, Isaac, Jacob, David, etc., the Jews remain a beloved people who will one day return and experience the full blessings of their covenant inheritance. Once the world is reconciled to God, then also the Jewish remnant will be fully included and this means the resurrection from the dead in Christ is at hand.
Not every single person who is of direct descent from Abraham is a part of the remnant as Paul made clear earlier (he hopes to save some of his fellow Jews via his ministry to the Gentiles), but it does seem the Jewish nation as a community and as a definable remnant will one day be mercifully fully included. The ESV reading plan also has selections from Ezra and Nehemiah, which illustrate this--a time of repentance for the remnant of God returning to Jerusalem. Not only individuals repenting, but the people together.