You've just given a lengthy argument to show that God went back on His Word. Yes, change came, but not change that makes God a liar.
Much love!
With the first advent of Christ, God introduced a new religious arrangement that changed the format of God’s engagement with man, and also enlarged the geographical range of His grace. Israel lost its exclusive privileged place under the new economy. The theocratic system was dismantled. The old covenant ceremonial system was replaced with a better, stronger, broader, more glorious and longer-lasting covenant. Under the new covenant there was absolutely no difference placed between Jews and Gentiles. Both enjoy equal status through faith in Christ. The New Testament expanded the Gospel thrust to embrace all nations. The new covenant knew no ethnic, political or religious boundaries. It was a global trans-national scheme that targeted a fallen world.
A lot of Christians today overlook this reality because they have a bias and faulty perspective of natural Israel. They make the mistake of viewing physical Israel today through Old Testament glasses. They fail to see that the Old Testament dispensation has gone forever and the New Testament era has fully and wholly superseded it. The old system has been totally dismantled and abolished because it was only ever intended to be a temporary covenant with an expiration date. Its conclusion occurred when Christ died on the cross. We see that with the ripping of the curtain in the temple at the very moment Jesus breathed His last breath (Matthew 27:50-51, Mark 15:37-38 and Luke 23:45-46). It therefore has no further purpose for time and eternity.
Under the new covenant, Gentile believers are being integrated into the citizenship of Israel. God’s promises and blessings have been extended beyond the righteous remnant of Israel to believing Gentiles who accept Christ as Lord and Savior. They are being grafted into the good Israeli olive tree by way of salvation throughout this intra-Advent period. Gentiles are being added to the household of Israel through faith in Israel’s Messiah. Under this Jewish umbrella, Gentiles enjoy favor with God and intimacy with Christ. They are now living stones in the New Testament temple. This renewed and expanded Israel includes countless Gentiles from all the nations of the world. The elect of God has grown from one single small physical nation in the Old Testament to incorporating millions of believers throughout the world today.
Ignorance of New Testament truth leads many to a distorted and erroneous understanding of Old Testament truth. Ironically, and paradoxically, especially allowing for how they describe themselves, many Futurists choose to live in the past. They understand ethnic Israel today in an old covenant sense, rather than a new covenant context. It is as if the old covenant is still active and valid and the new covenant has yet to arrive. Futurists seem unable (or unwilling) to recognize the seismic shift that occurred through the introduction of the new covenant. When pressed, they continually run back to the Old Testament for some type of support for a favored place for national Israel, a return of the Jews to their ancient land boundaries, the reintroduction of the old covenant apparatus, including a rebuilt physical temple, animal blood sacrifices, and a restored Old Testament priesthood. They have to pitch their tent in the Hebrew Scriptures because they have absolutely no endorsement in the New Testament for their theological model.
Sensible and enlightened Bible scholars place greater emphasis on the New Testament because it is the fuller revelation and it is where we now reside. God’s truth has been a gradual progressive unfolding and unveiling of truth to mankind from the beginning. The change and advancement that came with the New Testament era did not jettison the old Hebrew promises but rather fulfilled them. The doctrinal light became a lot clearer with Christ’s appearance and vivid illumination of the whole dynamic between the Old and the New Testament and the first and second advents. Our Lord removed the existing vail, dispelled the religious mist and has shed much-needed light on God’s redemptive plan.