Do you know that God changed Jacob's name to be henceforth called Israel, Gen 33:28?If that is the case, then you should believe that Israel refers to the nation Israel. The Body of Christ is separate from Israel.
Jacob/Israel is separate from the nation of Israel, and Jacob/Israel is representative of God's elect, Rom 9:11. and consists of every tongue, and kindred, and people, and nation, Rev 5:9.