...A partial hardening has come upon Israel, until the fullness of the Gentiles has come in.
Romans 11:25 ESV

God used the predisposition of the Jews to reject the Messiah to bring the good news of the Kingdom to the nations so that they might be blessed by Abraham’s seed scattered across the world. When the time is right, when God is done calling out to the nations and is ready to revive the genetic descendants of Jacob, he will sand off that callus, and they will know the truth.

(This is not Dispensationalism.)