Some treat Christianity as if Jesus had come to start a separate religion, but he came as the Jewish Messiah of Judaism in fulfillment of Jewish prophecy and he set a perfect example for us to follow of how to practice Judaism by walking in sinless obedience to the Torah. In Acts 21:20, they were rejoicing that tens of thousands of Jews were coming to faith in Jesus who were all zealous for the Torah, which is in accordance with Titus 2:14, where Jesus gave himself to redeem us form all lawlessness and to purify for himself a people of his own possession who are zealous for doing good works, so Jews coming to faith in Jesus were not ceasing to practice Judaism but were becoming zealous for it. This means that there was a period of time between the resurrection of Jesus and the incision of Gentiles in Acts 10 that is estimated to be around 7-15 years during which all Christians were Torah observant Jews and that Christianity at its origin was the sect of Judaism that recognized Jesus as the Messiah. In Acts 24:14, Paul testified that according to The Way, which they call a sect, he continued to worship the God of their fathers, believing everything laid down by the Torah and written in the Prophets, and the religion of which The Way is a sect is Judaism. While Jesus criticized some Pharisees with the heart behind some of the traditions they were following, that does not mean that he taught separate religion.
That wrongly assumes... that Judaism represents the true worship of God per the old covenant, and even is wrongly regarded as such by Jews today who reject Jesus of Nazareth as The Christ-Messiah. What didn't you understand with what Jesus said in those Scriptures I posted in my original post?