In the decades before and after Jesus’ life and death, there were dozens of messianic movements in Israel. In almost every case the messianic leader was killed, in many cases by execution, and after the leader’s death each of these movements invariably collapsed. Everybody went home, and that was it. Of all those dozens of movements, only one did not collapse after the death of the leader. Not only did it not collapse, it exploded: In the course of about 300 years it had spread through the entire Roman empire.
Christians would say it is because of what happened after the leader of this movement was killed. So what did happen to cause explosive growth in Christianity after its founder’s death?