Let's see... one thousand years ago, Verloren, the God of Death, sinned against the Chief of Heaven by killing his daughter. The Chief of Heaven banished him from the sky, so he wandered the world and created so much misfortune, that the Chief sent what we call "The Seven Ghosts". With their power, they were able to seal away Verloren's powers and stop the misfortune he brought to the world.

It wasn't a perfect fix, though- Verloren still sends demons and evil beings from his prison to influence people and get them to sin, so he can consume their souls. That's why the church was formed, and the bishops ordained- they're the only ones who can remove the Curse of Verloren.