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 Reading the Bible Supernaturally.
David Powlison worked for four years in psychiatric hospitals, during which time he came to faith in Christ. He serves as the Executive Director at Christian Counseling & Educational Foundation and edits The Journal of Biblical Counseling.