Israelites are still God’s people–to them belong the glory, the covenants, the law, the worship, and the promises. The welcoming of Gentiles does not mean God reneged on his promise to Israel, because Israel strove for righteousness under the law and fell short, whereas Gentiles attained righteousness through faith. Christ’s coming is the end of the law, and “everyone who calls on the name of the Lord shall be saved” (10:13). Many people who heard the gospel will not believe it, especially among Israel. Paul’s mission is to make some Israelites jealous by being an apostle to the Gentiles, so that some of them would convert and be saved through faith; these people will be the “remnant” of Israel. Eventually, when enough Gentiles have come into the church, all Israel will be saved, as they are God’s beloved people and will be shown mercy. Paul ends by an exhortation to morality: renew your minds to discern the will of God, don’t be judgmental, love one another, hate what is evil, be zealous, be hopeful and patient in suffering, and bless your enemies in order to overcome evil with good.
Commentary: In these chapters, Paul quotes extensively from the Old Testament to make his point. As usual for New Testament quotations of scripture, these quotations are not in context and should not be read as such. For example, in 10:13, “the Lord” refers to Jesus. But this is a quotation from Joel 2:32:
I will show portents in the heavens and on the earth, blood and fire and columns of smoke. The sun shall be turned to darkness, and the moon to blood, before the great and terrible day of Yahweh comes. Then everyone who calls on the name of Yahweh shall be saved; for in Mount Zion and in Jerusalem there shall be those who escape, as Yahweh has said, and among the survivors shall be those whom Yahweh calls (2:30-32)
Here, the Hebrew says YHWH (vocalized Yahweh, the personal name of God); it does not say “the Lord”, even though English translations use “the LORD”.
As another example, Paul’s “remnant” is a reference to Isaiah. There, the remnant refers to Israelites who survive Assyria’s conquest of the northern kingdom of Israel (Is. 10:20-22); Paul uses it to mean Jews in his own day who are unrighteous before God.