Where does God make the slightest inference that when He is talking about the literal, physical nation of Israel, and when making promises to the literal, physical nation of Israel, that that includes Gentiles? How did the promises God made to the Jews in the Old Testament, thousands of years before the Church was established, possibly apply to the Church? Where in Scripture do you get the idea that the promises made to Israel include the Church?
Where is your supporting Scripture? God's program through the Church didn't even begin until Acts (Matt 16:18; 1 Cor 12:13; Acts 1:5; 11:15-16) while His program through Israel began in Genesis 12. Where is the Scripture that supports your claim that the promises God made to Israel include the Church?
It doesn't include gentiles. It includes former gentiles who have been grafted into Israel through the shed blood of Christ.
This was always God's intent...even when he established ancient Israel:
Lev_19:34 The stranger who dwells among you shall be to you as one born among you, and you shall love him as yourself; for you were strangers in the land of Egypt: I am the LORD your God.
God never intended that there be some artificial wall erected by the Jewish religion....his intent was to make worship of him inclusive, not exclusive.
How did the promises God made to the Jews in the Old Testament, thousands of years before the Church was established, possibly apply to the Church?
I think you're confusing the Jewish religion with the Israel that the Lord established. As you can see from the scripture above they were quite different. By the time of Christ the Jewish religion had made it a crime to associate with "strangers" gentiles, much less love them.
I think also that you're creating an artificial wall between the "Church" and Israel. They are one and the same through Christ.
Where in Scripture do you get the idea that the promises made to Israel include the Church?
Eph 2:11 Therefore remember that you, once Gentiles in the flesh—who are called Uncircumcision by what is called the Circumcision made in the flesh by hands—
Eph 2:12 that at that time you were without Christ, being aliens from the commonwealth of Israel and strangers from the covenants of promise, having no hope and without God in the world.
Eph 2:13 But now in Christ Jesus you who once were far off have been brought near by the blood of Christ.
Eph 2:14 For He Himself is our peace, who has made both one, and has broken down the middle wall of separation,
Gal 3:16 "Now to Abraham were the promises spoken, and to his seed. He saith not, And to seeds as of many, but as of one, and to they seed which is Christ."
The promises would only be fulfilled in Christ THE seed (singular). Therefore whoever is in Christ is also a recipient of the promise.
This is not limited to an ethnic group (physical Israel and their law which was only a tutor until Christ came) but a spiritual group.
You are mistaken.