Franklin College in Franklin, Indiana, has been David's home for the past forty-three years. David has been particularly attracted to the topics of faith development, Catholic-Orthodox relations, and Christian-Muslim dialogue. In 2007, he conducted interviews across the country in monasteries and convents about monastic responses to 9/11. The book based on that experience, Peace Be with You: Monastic Wisdom for a Terror-Filled World, was chosen as one of the Best Books of 2011 by Library Journal. In the past sixteen years, religious terrorism has become an area of specialty. Much of his time in the last ten years has been spent giving talks as well as radio and television interviews on ISIS, Al-Qaeda, and other terrorist organizations.