(Philadelphia) -- The holidays can bring out the best and worst in people - including anger and bitterness. One pastor says letting go of negative emotions can actually help people improve their health and even fight cancer. As part of witf's Facing Cancer Together multimedia project, Dr. Michael Barry, director of Pastoral Care at Cancer Treatment Centers of America in Philadelphia talks about his findings and his new book, "The Forgiveness Project: The Startling Discovery of How to Overcome Cancer, Find Health, and Achieve Peace"