Why did Christians suffer massive Roman persecution while Jews did not?
Rome respected ancient religions, so Judaism, being ancient, was tolerated and even allowed to execute its own people. Christianity appeared as something new under the Roman Empire, not an ancient religion, so Rome tried every way to stamp it out, bringing Christians under massive persecution while Jews were spared.
Les explains that Rome had a lot of respect for ancient religions, including its own mythologies, and Judaism was an ancient religion. Rome therefore condescended to Judaism, protected the Jewish temple offerings, guaranteed safe delivery of money sent to Jerusalem, and even gave Jews permission to put their own people to death. That is why Paul could imprison and vote to put Jewish believers to death; Rome would never have allowed that to happen to a Gentile. But when Christianity made its appearance under the Roman Empire, it was not an ancient religion. It was something new, so Rome tried every which way to stamp it out. That is why Christians came under such massive persecution under Rome, and yet the Jews did not.