Why did Israel miss the Old Testament covenant promises?
Israel missed the Old Testament covenant promises because those promises were presented to them, but they rejected them when they crucified their Messiah. They departed in discord and disagreement and could not believe. As a result, the salvation of God was sent to the Gentiles, though individual Jews could still become believers.
Les teaches that by Acts 28, after Paul finished his missionary journeys and was imprisoned in Rome, he called for the Jewish leaders in Rome to meet with him. He went over all these things again, showing that all the Old Testament covenant promises had been presented to Israel, but they rejected them when they crucified their Messiah. They left in discord and disagreement and could not believe it. Then Acts 28 declares that the salvation of God is sent to the Gentiles, and they are going to hear it. Les explains that this does not mean all Gentiles will be saved, but they will hear it, and Scripture shows they have. That is why all the world stands guilty and why Romans 1 says they are without excuse, because they have heard. With the advent of the Apostle Paul going out, the calling is now predominantly Gentiles—Gentiles only with exceptions, and the exceptions are Jews. Jews can become believers of this Gospel, but they are few and far between. By far most of the calling out into the body of Christ is from among the Gentiles. Les says this is a complete flip-flop: formerly it was Jew only with some exceptions of Gentiles, but now it is Gentiles with some exceptional Jews coming in, as Paul says in Romans 11.