Why did Christ come to the nation of Israel?
Christ came to the nation of Israel to fulfill the Old Testament promises and covenants made to them. Israel was to be a kingdom of priests and a holy nation, acting as a go-between to lead Gentiles to a knowledge of God, and Peter pressed this claim on the nation after His crucifixion and resurrection.
Les explains that the verse calls Israel to be a kingdom of priests and a holy nation. A priest is a go-between. Since Israel already had its own priesthood, this priesthood was not between Israel and God but between the Gentiles and God. All through the Old Testament, God was preparing the nation for this national priesthood, where every Jew would be in a position to lead Gentiles to a knowledge of their God. At Pentecost in Acts chapter 2, Peter addressed Jews gathered from all over the Roman Empire and continued this frame of reference: Christ came to Israel to fulfill these Old Testament promises and covenants, and Peter made this claim on the nation even after Christ's crucifixion and resurrection.