Faith healing, or divine healing, is the use of spiritual means in treating disease, sometimes accompanied (in extreme instances) with the refusal of modern medical techniques. Another term for this is spiritual healing. Faith healing is a form of alternative medicine.
Faith healers are people who purport to use divine power to heal the sick and infirmed. Sam and Dean Winchester have not met any true faith healers, and Lucifer has revealed that all faith healers are fakes. It is likely humans lack the capacity to heal.
Desperate to save Dean after an accident leaves him with a damaged heart and weeks to live, Sam takes a skeptical Dean to visit Roy Le Grange. Soon after Dean is healed, the brothers discover that he is getting his healing powers from a reaper that is being controlled by La Grange's wife, Sue-Ann, who uses the reaper to kill people she deems unworthy and transfer their life to the "faithful." Upon Sam destroying the Coptic cross Sue-Ann used to control the reaper, the Reaper turns his attention to Sue-Ann and kills her, causing Roy to no longer be able to heal the sick.
The Winchesters and Castiel soon learn that "Peter Holloway" was in fact a Grigori by the name of Tamiel, who would take people who were looking to get healed and slowly consume their souls until they died.
Forced to panhandle due to his diminished grace and weakened state, Lucifer meets a young homeless man named Tim who takes pity on him and brings him to get food. Confused as to why they are going through a dumpster instead of using the money Tim received to buy food, Tim reveals he is saving up to visit Sister Jo to fix his injured leg. Surmising she is a faith healer, Lucifer tells Tim that all faith healers are fake. He is soon intrigued, though, when Tim describes the light that appears during the healing process.
Upon witnessing Sister Jo heal numerous people and seeing the glow emanate from her hands, Lucifer discovers that Sister Jo is really the angel Anael. He learns that after the Fall, Anael took to healing humans for money and carved out a life of her own on Earth.
- Faith healing on Wikipedia