Ruth Haley Barton is a spiritual director, teacher, author and retreat leader trained at the Shalem Institute for Spiritual Formation (Washington, D.C.). She is founder of the Transforming Center, a ministry of spiritual formation to pastors and Christian leaders, along with the congregations and organizations they serve. Educated at Wheaton College and Northern Seminary, Barton has served at several churches, including Willow Creek Community Church in South Barrington, Illinois. Her books include Sacred Rhythms, Longing for More and Strengthening the Soul of Your Leadership (all InterVarsity Press). Dallas Willard (1935-2013) was a professor in the School of Philosophy at the University of Southern California in Los Angeles for over forty years. A highly influential author and teacher, Willard was as celebrated for his enduring writings on spiritual formation as he was for his scholarship. His books include The Divine Conspiracy (Christianity Today?s Book of the Year in 1998), The Spirit of the Disciplines, Hearing God, Renovation of the Heart and others. His books have received numerous Christianity Today Annual Book Awards and other recognitions. Willard served on the boards of the C. S. Lewis Foundation and Biola University, and was a member of numerous evaluation committees for the Western Association of Schools and Colleges. He received bachelor?s degrees from both Tennessee Temple College and Baylor University and a graduate degree at Baylor University, as well as a PhD from the University of Wisconsin in Philosophy and the History of Science.