Again, important distinctions are called for in this important area. There is no doubt that alternatives to the "take 2 pills and call me tomorrow" brand of medicine have some validity. It is also probable, although far from proven definitively, that psychological states such as stress and happiness may influence what diseases we get and how easily they can be cured. Moreover, a certain percentage of people recover from quite serious illnesses for unknown reasons. Unfortunately, this has provided just enough "wiggle-room" for all sorts of claims to be made about the power of faith and other psychological states on health, despite fairly compelling empirical evidence against such claims. It is also important to remember that single cases of miraculous cures prove very little because in the absence of carefully controlled experiments one can never be sure what the real causes of the cure were. Some of the books listed below will step on the religious toes of people who belong to perfectly respectable religious organizations, but the fact remains that the scientific evidence for faith healing is minimal to non-existent. It is also not hard to document the fact that the founders of many religions based on faith healing were far from saints and had multiple motives for promoting their beliefs, although that does not directly affect the validity of their claims.
Numbers, Ronald L. Prophetess of Health: Ellen G. White and the Origins of Seventh-day Adventist Health Reform. University of Tennessee Press, 1992. A historian and son of an Adventist minister writes an interesting book on the creation of a new religion based in part on new and old ideas of health reform. Ms. White is not a heroine in this treatment.
Randi, James. The Faith Healers. Prometheus Books, 1987. Well-written, mostly case studies. There is some discussion of the history of faith-healing and its present relationship to various religions.