Protestants are clearly too dumb to grasp scripture.
https://scripturetruths5.tripod.com/spiritualisrael.html
Galatians 3:7   Therefore know that only those who are of faith are sons of Abraham.
Galatians 3:16   Now to Abraham and his Seed were the promises made. He does not say, "And to seeds," as of many, but as of one, "And to your Seed," who is Christ.
Galatians 3:28-29   There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus. (29) And if you [are] Christ's, then you are Abraham's seed, and heirs according to the promise.
Romans 9:6-8   But it is not that the word of God has taken no effect. For they [are] not all Israel who [are] of Israel, (7) nor [are they] all children because they are the seed of Abraham; but, "In Isaac your seed shall be called." (8) That is, those who [are] the children of the flesh, these [are] not the children of God; but the children of the promise are counted as the seed.
Romans 9:27   And Isaiah cries out concerning Israel: "Though the number of the sons of Israel be as the sand of the sea, only a remnant of them will be saved,
gospel,
Ephesians 3:5-6   ...the mystery of Christ, (5) which in other ages was not made known to the sons of men, as it has now been revealed by the Spirit to His holy apostles and prophets: (6) that the Gentiles should be fellow heirs, of the same body, and partakers of His promise in Christ through the gospel,
"apostles and  prophets" being one foundation points to one way of salvation throughout history [pre-cross & post-cross] - faith in Christ's finished work on the cross. Thus emphasizing one flock - Jew & Gentile believers [spiritual Israel].}
Ezekiel 16:3   "and say, 'Thus says the Lord GOD to Jerusalem: "Your birth and your nativity are from the land of Canaan; your father was an Amorite and your mother a Hittite.
{This verse also shows the concept of "one flock"(Jews & Gentiles). The father of the nation of Israel, Abraham, was actually a Gentile(Genesis 11:31). God chose(elected) Abraham from out of the whole world and made him into a great, blessed nation(Israel)(Genesis 12:1-2). These facts help to illustrate that the nation of Israel is used as a picture of the church, God's chosen people, as Romans 9:8 clearly shows - (Romans 9:8 -  That is, those who are the children of the flesh, these are not the children of God; but the children of the promise are counted as the seed.). Throughout the entire Old Testament God is showing us that He elects(chooses) a people for Himself, using national Israel as the illustration of this fact. "The children of the promise are counted as the seed"; God's chosen(elected) people is spiritual Israel(the church, the body of Christ), not national Israel.}