Why did Rome persecute Christians but not Jews?
Rome tolerated Judaism because it was an ancient religion, and Roman authorities respected ancient religions, even granting Jews authority to execute their own people. Christianity, however, appeared as a new religion under the empire, so Rome sought to stamp it out, bringing Christians massive persecution while Jews generally escaped it.
Les explains that Rome had respect for ancient religions, including its own mythologies, and Judaism was an ancient religion. Rome therefore condescended to Judaism, guaranteed safe delivery for Jewish offerings sent to the temple in Jerusalem, and even gave Jews permission to put their own people to death. Paul could imprison and vote to put Jewish believers to death, and Rome would never have allowed that to happen to a Gentile. But when Christianity appeared 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 massive persecution under Rome, and yet the Jews did not.