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 Foundations for Lifelong Learning: Education in Serious Joy.

Nancy Guthrie attends Cornerstone Presbyterian Church, in Franklin, Tennessee, and teaches at conferences around the country and internationally, including her Biblical Theology Workshops for Women. She and her husband host Respite Retreats for couples who have faced the death of a child and are co-hosts of the GriefShare video series.

Greg Lucas is a police officer in West Virginia, a graduate of Boyce college, and a Bible teacher and advisor for The Elisha Foundation, which encourages families experiencing disability toward a more intimate faith in Christ. He is also the author of Wrestling with an Angel: A Story of Love, Disability, and the Lessons of Grace. Greg and his wife, Kimberly Ann, have four children.

Mark Talbot (PhD, University of Pennsylvania) is an associate professor of philosophy at Wheaton College and the host of the podcast When the Stars Disappear. He is also the author of When the Stars Disappear and Give Me Understanding That I May Live.