David Miller is Founder of Line Upon Line Ministries. David has been preaching for over 50 years. He has been in full-time evangelism since 1995 with Line Upon Line Ministries. He prefers the title “Country Preacher at Large.” He resides in Heber Springs, Arkansas, with Glenda, his wife of 50 years. He has a son, Josh, who is married to Bethany. He also has a grandson, Malachi. David is an avid hunter deer and elk and loves being outdoors.

Joel Beeke was converted at the age of 14, and has pastored for more than forty years in three churches. Currently, he is president and professor of  systematic theology and homiletics at Puritan Reformed Theological Seminary (since 1994), a pastor of the Heritage Reformed Congregation in Grand Rapids, Michigan (since 1986), editor of Puritan Reformed Journal and Banner of Sovereign Grace Truth, editorial director of Reformation Heritage Books, president of Inheritance Publishers, and vice-president of the Dutch Reformed Translation Society.

Paul Washer became a believer while studying at the University of Texas.  After graduating, he moved to Peru and served there as a missionary for ten years, during which time he founded the HeartCry Missionary Society in  order to support Peruvian church planters. HeartCry’s work now supports indigenous missionaries throughout Africa, Asia, Europe, the Middle East,  Eurasia, North America, and Latin America. Paul now serves as one of the  laborers with the HeartCry Missionary Society. He and his wife Charo have four children: Ian, Evan, Rowan, and Bronwyn.

Steven J. Lawson is founder and president of OnePassion Ministries, a ministry designed to equip and energize a new generation of Bible expositors. Dr. Lawson is a Teaching Fellow with Ligonier Ministries, Professor of  Preaching and Dean of the Doctor of Ministry program at The Master’s Seminary, and Executive Editor for Expositor magazine. He is also on the board of The Master’s University and Seminary, Ligonier Ministries, and Reformation Bible College.

Tim Challies is a Canadian Reformed theologian, pastor, blogger, and author. Challies was an early adopter of the blog format and continues to write with a focus on theology, book reviews, and social commentary.

Trevin Wax is vice president of research and resource development at the North American Mission Board and a visiting professor at Wheaton College.

Voddie Baucham is Dean of Theology at African Christian University, Zambia.