David G. R. Keller, an Episcopal priest, is adjunct professor of ascetical theology at the General Theological Seminary in New York City. He is co-steward, with his wife, Emily Wilmer, of Oasis of Wisdom: An Institute for Contemplative Study, Practice, and Living based in Asheville, North Carolina (www.oasisofwisdom.net). He is the author of Oasis of Wisdom: The Worlds of the Desert Fathers and Mothers (Liturgical Press) and Come and See: The Transformation of Personal Prayer (Morehouse Publishing).