The two main causes of the fall of the Roman empire (suggested by Edward Gibbon) are the adoption of Christianity and the economic decline. Although there are many different theories of what could have happened (and it's undoubtedly more than one thing), these are two of the most important factors that led to Rome's decline.
Religion was an issue that caused a lot of conflict in Rome. Most of it started when Israel became occupied by Romans. It had been conquered many times before, but was now ruled by a world power whose primary religion was Christianity. Around 14-30 ce, the Jews living in Israel were exempt from Roman emperor worship, but soon after that, Jesus, a Jewish reform prophet, was arrested; he posed a threat to the Roman empire
Religion was an issue that caused a lot of conflict in Rome. Most of it started when Israel became occupied by Romans. It had been conquered many times before, but was now ruled by a world power whose primary religion was Christianity. Around 14-30 ce, the Jews living in Israel were exempt from Roman emperor worship, but soon after that, Jesus, a Jewish reform prophet, was arrested; he posed a threat to the Roman empire