You can read about it yourself in the Bible, in the Council of Jerusalem circa AD 50, which is covered in the Acts of the Apostles. That seems as good a date as any, since that is when we formally decided among ourselves that we are not to be under the vast majority of Jewish law (which, remember, formed the understanding of who was and wasn’t a Jew for the Jews of that time, as it does for most observant Jews today). Of course groups of “Jewish Christians” or Judaizers lasted for much, much longer than that and in some places they were quite influential (like the Ebionites, who existed up until about the 12th century in Arabia and had a huge influence on the Islamic view of Jesus). Some could say that they’re still with us today thanks to “Jews for Jesus” or similar groups within the ‘Hebrew Christian’ movement, though to be honest the vast majority of those are not Jewish Christians in the way the earlier Judaizers would’ve thought, but rather pop evangelicals who like menorahs and saying “Hanukkah” with an extra-harsh Khhhhhh at the beginning, as though they’re Ashkenazis…pretty silly, I think.
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