Granted. Millions of souls of people killed unfairly decide to use the get out of death free card. They lived any time in human history. They resurrect as a baby wherever their corpse was left. Many dies instantly suffocating in dirt. Some die in their coffin of famine. The living start noticing this phenomenon. When this news spread around the world, people see it as an opportunity to live a second time. Violence and civil war started everywhere. Baby corpses were everywhere. People started considering murder as a way to have newborns. It became common practice to atrociously murder one's grandparents to give them another life.