Rom 9:6
6 Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
No, The Church has always been Israel, but not Israel after the flesh, or the physical nation of Israel See within the physical nation of Israel was always a remnant according to the election of Grace, which is also Israel. Now under the Old Covenant Spiritual Israel, the Body of Christ was mostly comprised of saved jewish Christians. They would usually be persecuted by the non christian jews in the nation Matt 5:12
Rejoice, and be exceeding glad: for great is your reward in heaven: for so persecuted they the prophets[Believers in Crist] which were before you.
Lk 13:34
O Jerusalem, Jerusalem, which killest the prophets, and stonest them that are sent unto thee; how often would I have gathered thy children together, as a hen doth gather her brood under her wings, and ye would not!
Now under the New Covenant, Body of Christ Israel the election of Grace has been multiplied by saving and grafting in multitudes into Spiritual Israel, which is still the Body of Christ ! So The Body of Christ, Israel according to the Spirit, the Election of Grace is not a replacement, it always has been, its now clarified who they are.