Nathan D. Holsteen, ThM, PhD, is Associate Professor of Theological Studies at Dallas Theological Seminary, where he teaches all areas of systematic theology. Trained as an engineer, he is awed by systems of theology that exhibit internal coherence. He and his wife, Janice, have two children and live in Fort Worth, Texas.Michael J. Svigel, ThM, PhD, is the Department Chair and an Associate Professor of Theological Studies at Dallas Theological Seminary. He has written numerous Bible study guides, articles, and papers, and is the author of RetroChristianity. He lives in Garland, Texas, with his wife, Stephanie, and their three children. Learn more at www.retrochristianity.com.