John Piper is founder and teacher of desiringGod.org and chancellor of Bethlehem College & Seminary. For 33 years, he served as pastor of Bethlehem Baptist Church, Minneapolis, Minnesota. He is author of more than 50 books, including Desiring God: Meditations of a Christian Hedonist and most recently What Is Saving Faith?

Mark Noll is retired as a history professor from Wheaton College and the University of Notre Dame.