I'm so glad you asked!
The "church" is a
Jewish society and is the faithful jews, who exist all the way back at the time of Moses (
Acts 7:38). Jesus tells the Jewish apostles at Matt 16:18-19 that Peter was commanding God's church in his day, even as Moses had done so in his generation (
Acts 7:38). None of the apostles knew of gentile inclusion into the Church until years after Pentecost. The Church was the Nazarene sect of the Jews of first-century Israel who entered into Messiah's New Covenant, as had been prophesied to Israel.
You however, seem to have a bizarre idea of who is Israel (as I mentioned, you count the disobedient sons of Abraham as Israel while
discounting entirely the faithful sons of Abraham).
St. Paul said that when the nation was in mass apostasy, the TRUE Israel was carried on
not through the lineages of the wicked sons but rather through the OBEDIENT FEW (called the "remnant"), such as was true in Isaiah's day (
Romans 9:27-29) and Elijah's day (
Romans 11:3-5).
Peter says the same thing at
Acts 3:22-24, where it is clear that the wicked jews who refuse Christ were to be "cut off from among the People of Israel" while the faithful jews (John the Baptist, Joseph and Mary, the Twelve, the Seventy, the three thousand on Pentecost day, and many other jews)
were the True Faithful Israel.
Just as the jewish church abode with Moses in the wilderness (
Acts 7:37-38), so Jesus had HIS jewish church (Mt. 16:18-19). And within a few years after Pentecost, the faithful Israel learned how to start accepting both jewish and also gentile followers from all over the empire to convert into their Nation (
1 Peter 2:9-10; Mt 21:40-45). And so the tiny remnant True Israel grew into a
worldwide Judaism living under the promised NEW covenant of Israel's Messiah.
And, to my original point you asked about, so it was also in Moses' day, when the countless thousands of wicked sons of Abraham were slain in the wilderness while the faithful sons of Abraham survived and got to enter the Promised Land.
We must NEVER count the continuation of Israel through the wicked sons but rather always through the faithful remnant!
This is your mistake.
You are claiming the Wicked Sons are to be counted as "True Israel" while the Faithful remnant Sons are NOT True Israel. Which, as I said, is JUST like saying the wicked thousands that rejected Moses and were slain in the wilderness are true Israel, and the faithful remnant that survived to enter the promised land are NOT true Israel.
Such is the TRUE replacement theology...you have replaced faithful Israel with some other group that Moses, Jesus and the apostles would not recognize.
Finally, in real historic terms, that means that the Nazarene Jewish sect (
Acts 24:5) was the only one that survived AD 70. All the other sects---Sadducees, Essenes, Pharisees, Zealots--were destroyed and went extinct at AD 70. This is historic reality, as Jewish and secular histories admit. And it is quite remarkable that what saved the Nazarenes was their NEW covenant teaching that taught them to prepare to detach from animal sacrifices, the Temple, physical circumcision, and the priestly class of Aaron. The jews who did this survived AD 70 while the ones who clung to a salvation via the Old Covenant were all wiped out. Amazing history.