The Healing Power of Faith-How Belief and Prayer can Help you Triumph Over Disease. Harold B. Koenig, M.D. Koenig an advisor to the Mary Baker Eddy Library, he is certified in family medicine, psychiatry, geriatric medicine, and geriatric psychology. Today, as head of the Duke University’s Center for the Study of Religion/Spirituality and Health, he’s overseen more than 50  major research projects on the relationship between faith and health, and 70 data-based, peer-reviewed papers in medical and scientific journals.