You are completely ignoring the fact that verse 28 explicitly defines the group under discussion at that point as those that "are enemies for the gospel's sake." Yet, even these enemies, it explicitly says are "beloved for the father's sake." it is only then that it gives the reason, that "the gifts and calling of God are irrevocable." Do you realize what "irrevocable" means? It means that the ancient promises cannot be revoked. Period. no exceptions.
This is what the Holy Spirit explicitly says.
It has no reference to ancient promises, for the gifts and the calling are terms associated exclusively with those who have put their faith in Christ.
Upon whom does God bestow His gifts?
Romans 12:6
Having then
gifts differing according to the grace that is given to us, whether prophecy, let us prophesy according to the proportion of faith;
1 Corinthians 12:1
Now concerning spiritual
gifts, brethren, I would not have you ignorant.
1 Corinthians 12:4
Now there are diversities of
gifts, but the same Spirit.
1 Corinthians 12:9
To another faith by the same Spirit; to another the
gifts of healing by the same Spirit;
1 Corinthians 12:28
And God hath set some in the church, first apostles, secondarily prophets, thirdly teachers, after that miracles, then
gifts of healings, helps, governments, diversities of tongues.
1 Corinthians 14:12
Even so ye, forasmuch as ye are zealous of spiritual
gifts, seek that ye may excel to the edifying of the church.
God's gifts were, and are, not bestowed upon Paul's countrymen according to the flesh, enemies of the gospel.
They are bestowed exclusively upon God's "all Israel" remnant of His Holy Chosen People -- His Church.
To them, and to no others, His gifts are irrevocable.
To whom is God's calling directed?
1 Corinthians 1:26
For ye see your
calling, brethren, how that not many wise men after the flesh, not many mighty, not many noble, are called:
1 Corinthians 7:20
Let every man abide in the same
calling wherein he was called.
Ephesians 1:18
The eyes of your understanding being enlightened; that ye may know what is the hope of his
calling, and what the riches of the glory of his inheritance in the saints,
Ephesians 4:4
There is one body, and one Spirit, even as ye are called in one hope of your
calling;
2 Thessalonians 1:11
Wherefore also we pray always for you, that our God would count you worthy of this
calling, and fulfil all the good pleasure of his goodness, and the work of faith with power:
2 Timothy 1:9
Who hath saved us, and called us with an holy
calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began,
Hebrews 3:1
Wherefore, holy brethren, partakers of the heavenly
calling, consider the Apostle and High Priest of our profession, Christ Jesus;
2 Peter 1:10
Wherefore the rather, brethren, give diligence to make your
calling and election sure: for if ye do these things, ye shall never fall:
God's calling was, and is, not directed to Paul's countrymen according to the flesh, enemies of the gospel.
It is directed exclusively to God's "all Israel" remnant of His Holy Chosen People -- His Church.
To them, and to no others, His calling is irrevocable.
This is an unequivocal repudiation of any claim that unbelievers within the nation of Israel, enemies of the gospel, can be the recipients of God's gifts and calling.