In harmony with verses 25, 26, which speak first of a hardening of part of Israel and then about “all Israel” which will be saved, so here too the apostle first reminds us of those Israelites who, as far as the gospel is concerned, are enemies, and then of those who, as far as election is concerned, are beloved for the sake of the fathers. In reading on (see verses 30, 31), however, we soon become aware of the fact that these “enemies” and these “beloved ones” are the same people, namely, the elect. At first they were hostile to the gospel, but later on, because of the wonderful manifestation of God’s mercy (see verse 25 f.) they become friends.
Note the following:
a. “As far as the gospel is concerned … enemies for your sake.” Note “for your sake.”
The explanation is found in verse 11: “Because of their trespass salvation (has come) to the Gentiles.”
b. “… as far as election is concerned, they are beloved.”
The same Jews who at one time had been enemies of the gospel had become friends, beloved of God and fellow-believers. This great change had been through about because of the fact that these former enemies had been designed by God, in his eternal decree, to become friends.
c. “for the sake of the fathers.”
Not because of any innate goodness or merit pertaining to Abraham, Isaac, and Jacob, but because of God’s promise to the fathers, “I will … be your God and the God of your seed after you” See Gen. 17:7; cf. 26:23, 24; 28:12–15.
d. “for irrevocable are God’s gracious gifts and his calling.”
There are those who interpret this entire passage (verse 28–31) as a description of God’s love for the people of Israel in general. The present clause shows that this interpretation is incorrect, for it refers to God’s irrevocable calling, a call that is not subject to change and is never withdrawn. This is certainly the inner or effectual call, one that pertains only to the elect.327
e. This also proves that “God’s gracious gifts” must not be identified, as often happens, with the special privileges granted to the Jews as a people (9:4, 5), but must refer to such products of God’s special grace as faith, hope, love, peace that surpasses all understanding, life everlasting, etc., all of them being gifts bestowed on God’s elect, on them alone.
f. The explanation of the words, “For just as at one time you were disobedient to God but now have received mercy as a result of their disobedience, so they too … may now receive mercy,” is found in verse 11; note especially “to make Israel envious,” and see the explanation of that verse on p. 367.
g. It is clear that the entire passage (verses 28–31), correctly explained, harmonizes with 11:26a, “And so all Israel will be saved.” In both cases Paul is speaking about the true Israel. They are enemies (at first). They are beloved … have become disobedient in order that they too may now receive mercy. The apostle is telling the Romans, especially the Gentiles among them, who in all probability constituted the majority of the congregation, that, as a result of the mercy shown to them—that is, to this predominantly Gentile church—the Jews, stirred to envy, now receive God’s mercy, his love to those in need.
h. The repetition of the word now, occurring either twice or three times in verses 30, 31, shows that all the while Paul is thinking not of something that will happen at, or just previous to, Christ’s Return, but of events that are occurring right now, in fulfilment of God’s plan from before the founding of the universe.
William Hendriksen and Simon J. Kistemaker, vol. 12-13, New Testament Commentary : Exposition of Paul's Epistle to the Romans, Accompanying Biblical Text Is Author's Translation., New Testament Commentary (Grand Rapids: Baker Book House, 1953-2001), 384.