One first must know what God's promises to Israel involve according to His Word. It involves a lot more than just the lands of promise. Israel is the name of Christ's future inheritance and it very much involves His Church. It is the name through which God's Birthright promises are committed, even today.
The error in many's thinking is in continually misapplying the name Israel to the unbelieving, like Jews who refuse Christ Jesus. In Romans 11:1-5, Apostle Paul showed that just as in Elijah's day God had preserved 7000 of Israel to Himself that had not bowed the knee to Baal, likewise in Paul's day there was a remnant of Israel according to the election of grace. That's enough for the promises to still be in effect towards.
With the spiritual Israel concept in Romans 9, Apostle Paul is showing just how God's promises to Israel have continued, and will continue for ever, through Christ Jesus. This is why Paul uses the title of "the commwealth of Israel" in the New Testament Book of Ephesians about Christ's Church. This is why our Lord Jesus promised that each of His 12 Apostles would sit upon thrones in His Kingdom judging over one of the 12 tribes of Israel.
This is why our Heavenly Father said the following that Israel will be a nation before Him forever...
Jer 31:35-37
35 Thus saith the LORD, Which giveth the sun for a light by day, and the ordinances of the moon and of the stars for a light by night, which divideth the sea when the waves thereof roar; The LORD of hosts is His name:
36 If those ordinances depart from before Me, saith the LORD, then the seed of Israel also shall cease from being a nation before Me for ever.
37 Thus saith the LORD; If heaven above can be measured, and the foundations of the earth searched out beneath, I will also cast off all the seed of Israel for all that they have done, saith the LORD.
(KJV)
In Ezekiel 47-48, which is after Christ's coming, anyone who can read can easily see how that's about the 12 tribes all being joined back to the original inheritances of land which God promised their fathers. So debates that go directly against those Scriptures are a waste of time. God has ordained it, He has declared, it will happen as written.
So where's the promises, and what are they? And where are they today, among whom? I am surprised that so few know how our Lord Jesus moved those promises, not putting an end to them just because many of Israel didn't believe.