It is recorded in the classics: People have life span, ghosts have ghost life span. Ghosts take away the life span of humans to increase their own life span, and people can also take away the life span of ghosts to increase the life span of human beings. However, it is evil to take away one's lifespan, and the way of heaven does not tolerate it, causing one's soul to scatter and disappear into heaven and earth. If one helps the ghosts to be saved, it is a great good deed, but the loss of one's lifespan can be offset later.