The Catholic Church and Christians associated with them in Jewish-Christian dialogue have recognized over the past 50 to 60 years that reflection on where the Church has been in relation to Judaism and where both are going is necessary.
There have indeed been changes to both, but the changes don’t negate that God still works with his people. For instance, the original Jerusalem congregation consisted of Jewish Christians that were Torah-observant. According to the Scriptural testimony, the apostle Paul made a public act of worship in the Jewish Temple to demonstrate that his ministry to the Gentiles and his teaching to them (contained in many of the epistles) did not fully apply to followers of Jesus who were of Jewish stock.–Acts 21:17-26.
The Jerusalem church remained until the year 135 C.E./A.D. when the Romans crushed the Bar Kokhba rebellion and banned all Jews from Jerusalem. This included the Jewish Christians. The last Jewish bishop of Jerusalem was Judah Kyriakos (who was the great grandson of St. Jude the Apostle), and little to nothing is known of what happened to him and the Jewish Christians after this.
Eventually a great divide occurred between Judaism and Christianity. It culminated over the centuries into actual hatred between the two, and sadly climaxed into the anti-Semitism that ran amuck through Europe in the 20th century, climaxing in the horrors of the Shoah.
Since then bridges have been built in dialogue between Jews and Christians. Among Judaism and the Catholic Church a new understanding has developed. In mutual fraternal dialogue the Catholic Church recently recognized the following:
“In the past, the break between the Jewish people and the Church of Christ Jesus could sometimes, in certain times and places, give the impression of being complete. In the light of the Scriptures, this should never have occurred. For a complete break between Church and Synagogue contradicts Sacred Scripture.”–
The Jewish People and Their Sacred Scriptures in the Christian Bible.
There are still many Christians of Jewish descent among Catholics who live as children of both worlds, myself included. Many are descendants of the Conversos who were expelled from Spain by promulgation of the Alhambra Decree of 1492. At the dawn of the 21st century Spain and Portugal began actively seeking ways to repair the wrong that occurred, offering restored citizenship to these descendants many of which are considered “Crypto-Jews” who despite being Catholic have kept their Jewish customs alive and well over the centuries. (A similar resolve is currently being considered by the State of Israel.) Some today live much like the original Jerusalem Christian community did in the first century.
Whatever negative changes have occurred among the two have not been so great that Divine Providence has been unable to overcome them. While neither side is currently claiming to have all the answers, many in Judaism and the Catholic Church have come to understand that God’s redemption appears to exceed greatly beyond the limits of denominational lines and theological differences.
For more on this you may want to read two important statements released at the end of 2015, one from the Holy See and the other a statement from Orthodox Rabbis.
“The Gifts and Calling of God are Irrevocable”–Catholic Commission for Religious Relations with the Jews.
Orthodox Rabbinic Statement on Christianity