This issue came up in some teaching I did recently. Why did Jesus instruct his disciples not to go in the way of the Gentiles or to the towns of the Samaritans but only to the “lost sheep of the house of Israel” (Matt. 10:5-15)? Doesn’t that contradict the “great commission”, when the disciples are sent out into the whole world to make disciples of all nations? Students tended to resolve the problem by arguing that the kingdom was offered first to Israel as God’s chosen people and then to everyone else. That seems to me to be at best half right and to entail a mistaken notion of the kingdom of God.
The underlying assumption seemed to be that kingdom is roughly equivalent to salvation. It is a wonderful new thing that is held out to humanity on the grounds of the death of Jesus, and it is only really an accident of “salvation-history” that the Jews got first bite of the cherry.
This gets both kingdom and salvation wrong. The mission of the disciples in Matthew is meaningful only on the assumption that “kingdom” is and remains an integral part of Israel’s story. It is not something extraneous that is offered to Israel first like a cream cake, which they turn down because they are dyed-in-the-wool legalists, and it’s then passed round to the Gentiles, who scoff it gratefully. In fact, I would say, the story of Israel is the story of kingdom. Or it’s the story of how to fail and succeed at cake making.