“Therefore remember that at one time you Gentiles … were … separated from Christ, alienated from the commonwealth of Israel and strangers to the covenants of promise, having no hope and without God in the world.” – Ephesians 2:11-12
When reading this statement by Paul, in his mind, being separated from Christ means being separated from the commonwealth of Israel and the covenants of promise. They are all one in the same. The promise made to Noah, Abraham, Isaac, Jacob, Moses, and the prophets, is the same promise we Gentiles inherit through faith alone in Christ alone. We are grafted into the Vine, which is Christ. We become a part of Israel, that is, God’s saved people for all time. There is no segmentation of Israel versus Gentiles. Christ has brought that wall down and we are the same: Israel, the people who have believed God and are reckoned as righteous on the basis of the righteousness of Another, Christ.