The mass conversion of Israel toward the end of the world is a well-known prophecy among the Saints.
Firstly, the true Israel is the Catholic Church. It's not a geographical land mapped out by the United Nations in 1948. The Catholic Church is, essentially, the Bosom of Abraham. Just as before the Son became flesh and dwelt among us, only the righteous in the Bosom of Abraham were to be saved when Christ opened the gates of Heaven for them by His Divine Sacrifice, it is only baptized Catholics, who die in the state of grace, who enter Heaven.
Secondly, what mass conversion? "Mass" is a relative word. Only a minority of the ѕуηαgσgυє of Satan will convert to the Catholic Church before Jesus returns. Two-thirds of the Jews will be exterminated as punishment for their rejection of God. This is the prophesy. It's in Zacharias 13:8-9
sedevacantist says:
The conversion of the descendants of Israel, then, is a well known prophecy.
What descendants? After the Diaspora, the ѕуηαgσgυє lost their biological lineage to David when they mixed with, and converted, Khazars and, subsequently, mixing with some locals of European host nations. They're not biologically descended from David, nor are they spiritually descended from Abraham, for if they were the latter, they would have accepted Jesus Christ as the only true God and Messiah.
sedevacantist says:
Moreover, as everyone knows, the Israelites are the “Firstborn” of God.
Your fallacy is conflating the true Israelites who lived before, and at the time of, Jesus Christ, with the ѕуηαgσgυє of Satan, who are those who say they are Jews, but lie (Revelation 2:9 & 3:9).
Try learning the Catholic Faith before you espouse your subtle Jew apologetics and Zionism.