Robert L. Thomas has lived in Stanton, California, for fifty-three years, 49 of those years with his now-deceased wife Joan who was promoted to glory in 2008. He has been a member of the Anaheim Community Church throughout this period. He has five children, all of whom are married, fifteen grandchildren three of whom are married, and five great-grandchildren. After being reared in Decatur, Georgia, he earned an engineering degree from Georgia Tech in 1949 and received from Dallas Theological Seminary his Th.M. in 1956 and his Th.D. in 1959, after taking work at Moody Bible Institute and Faith Theological Seminary also.
He served as a Professor of New Testament at Talbot School of Theology for 28 years and as Professor of New Testament at The Master’s Seminary for 23 years. At Talbot he was Secretary to the Faculty for approximately twenty-five years. After moving to The Master's Seminary, he was instrumental in starting The Master's Seminary Journal, for which served as Executive Editor for 21 years. His faculty role at The Master’s Seminary ended in 2009 with a commendation from President MacArthur for integrity and a positive impact on the Seminary.
He was National President of the Evangelical Theological Society in 1989-90. He was a translator for the New American Standard Bible during the 1960s and is General Editor of the New American Standard Exhaustive Concordance (Holman, 1981, more recently published in 1998 by Zondervan as The Strongest NASB Exhaustive Concordance) which received the Gold Medallion Book Award from the Evangelical Christian Publishers Association as the outstanding reference work of 1981-82. His publications include "1, 2 Thessalonians" in the Expositor's Bible Commentary (Zondervan, 1978), A Harmony of the Gospels for both the NASB (Harper-Colins, 1978) and the NIV (Harper-Collins, 1988), Revelation 1–7, An Exegetical Commentary (Moody, 1992), Revelation 8–22, An Exegetical Commentary (Moody, 1992), and The Jesus Crisis (Kregel, 1998). His most recent works are Understanding Spiritual Gifts, A Verse-by-Verse Study of 1 Corinthians 12–14 (revised edition, Kregel, 1999), How to Choose a Bible Version (Mentor Series for Christian Focus Publications, 2000), Charts of the Gospels and the Life of Christ (Zondervan, 2000), Who Am I? Christian Hunger for Self-Identity (Mentor Series for Christian Focus Publications, 2002), and Evangelical Hermeneutics (Kregel, 2002). While currently pursuing other writing projects, he is an active member of Anaheim Community Church in California.
In 2011 he received the John F. Walvoord Lifetime Achievement Award for Excellence in Prophetic Studies from the Pre-Trib Research Center of Dallas, Texas.