Why did the Jews persecute Paul so relentlessly?
They persecuted Paul because he taught that Gentiles were just as good as Jews and that there is no difference between Jew and Gentile in salvation. This infuriated a people who for nearly 2000 years had been taught they were God's special, set-apart covenant people. His message that no one is righteous also struck at their self-righteousness.
Les explains that the Jewish community was sent into orbit because Paul told people that Gentiles are just as good as Jews. For almost 2000 years they had heard that they were special, God's covenant people, set apart from the rest of the world, not to intermarry, and to stay within their tribes. So when this little Jew came out and said there is no difference, it infuriated them that he was now attempting to take the salvation of Israel's God to pagan Gentiles. They followed him from city to city, tried to defeat him in any way they could, and plagued him until his death. Les also notes that when Paul wrote, "There is none righteous, no not one," the Pharisees could have put him to death, because they were righteous in their own eyes, but he made it plain that no one is righteous—not even the most religious Jew. This was the crowning reason he put something like this out there: there is no difference now between Jew and Gentile.
More Questions
What did the Jews do to the Apostle Paul throughout his ministry?
The Jews plagued the Apostle Paul every step of his way, following him from city to city and trying to defeat him until his death.