I would suggest to you that the Jews as a physical people are no longer God's people. Who was more a Jew than Paul? Yet he abandoned it all for Christ.
Phil. 3:2 Beware of the dogs, beware of the evil workers, beware of the false circumcision; 3 for we are the true circumcision, who worship in the Spirit of God and glory in Christ Jesus and put no confidence in the flesh, 4 although I myself might have confidence even in the flesh. If anyone else has a mind to put confidence in the flesh, I far more: 5 circumcised the eighth day, of the nation of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; as to the Law, a Pharisee; 6 as to zeal, a persecutor of the church; as to the righteousness which is in the Law, found blameless.
7 But whatever things were gain to me, those things I have counted as loss for the sake of Christ. 8 More than that, I count all things to be loss in view of the surpassing value of knowing Christ Jesus my Lord, for whom I have suffered the loss of all things, and count them but rubbish so that I may gain Christ, 9 and may be found in Him, not having a righteousness of my own derived from the Law, but that which is through faith in Christ, the righteousness which comes from God on the basis of faith,
The things of the OT were for our learning. There were two people in the OT, Jews and Gentiles. Jews were God's people and Gentiles were not. Same for today, Christians are God's people and everyone else is not.
I suggest the church and the kingdom are the same. Jesus used them interchangeably as did Paul.
Matt. 16:18 I also say to you that you are Peter, and upon this rock I will build My church; and the gates of Hades will not overpower it. 19 I will give you the keys of the kingdom of heaven;
Acts 20:25 "And now, behold, I know that all of you, among whom I went about preaching the kingdom, will no longer see my face….28 Be on guard for yourselves and for all the flock, among which the Holy Spirit has made you overseers, to shepherd the church of God which He purchased with His own blood.