What did God do when Israel rejected the Gospel of the Kingdom and crucified the King?
When Israel rejected the Gospel of the Kingdom and crucified the King, God turned to Saul of Tarsus, the Apostle Paul, who began to proclaim the Gospel of Grace. This message is primarily to the Gentiles, and through it God calls out the Body of Christ rather than a covenant nation.
Les explains that the good news was that Christ was the King in Israel's midst, ready to fulfill all the Old Testament promises concerning Israel and His Messiahship. That was the Gospel of the Kingdom, and it was for Jew only; there was nothing in it for the Gentile. When Israel rejected the Gospel of the Kingdom and the King, and they crucified Him, God turned to this other Jew, Saul of Tarsus, the Apostle Paul, and he begins to proclaim the Gospel of Grace. That Gospel of Grace means nothing of law or legalism can be associated with it, and it is primarily, not exclusively, to the Gentiles. Through the preaching of the Gospel of Grace, instead of calling out a covenant people such as Israel was, God is calling out what Paul refers to as the Body of Christ. Jesus or the Twelve never use the term Body of Christ; they did not know about it and did not use the term, though Jesus knew about it, He never revealed it.