Cosby, Messner Appointed at RTS Atlanta

Brian Cosby
Dr. Brian Cosby
Aaron Messner
Rev. Aaron Messner

(MARIETTA, Ga.) – The Board of Trustees of Reformed Theological Seminary is pleased to announce that Dr. Brian Cosby and Rev. Aaron Messner have been appointed as adjunct professors at RTS Atlanta. Dr. Cobsy is Adjunct Professor of Historical Theology and Rev. Messner is Adjunct Professor of Pastoral Theology.

Dr. Guy Richard, President of RTS Atlanta, shared, “Aaron and Brian have been teaching for our campus for several years now and have become integral to what we are doing. I am pleased to be able to recognize officially the important part they play in our campus life by appointing them to be adjunct faculty. Their appointment not only reflects the value that they add in the classroom but cements our relationship with them even further so that future students can benefit from their influence for years to come.”

Dr. Brian Cosby

Dr. Cosby serves as senior minister of Wayside Presbyterian Church (PCA) on Signal Mountain, Tennessee. In addition to teaching at RTS, he has taught as an adjunct professor at Covenant College and at Belhaven University (Chattanooga, Tennessee). Dr. Cosby is a chaplain (Capt.) in the United States Air Force Reserves. He also serves on the board of trustees for Covenant Theological Seminary in St. Louis, Missouri.

Dr. Cosby is a content writer for Ligonier Ministries’ online and print publications and editorial director for the Gospel Reformation Network. He has also written over a dozen books. His academic interests include Reformation and post-Reformation/Puritan history, theology of suffering, and confessional theology. He and his wife, Ashley, have three children.

Dr. Cosby earned his B.A. from Samford University and his MDiv from Beeson Divinity School. He graduated with his Ph.D. from the Australian College of Theology. When asked about his appointment as adjunct professor, Dr. Cosby shared, “I am honored to be a part of the RTS family and am delighted to serve the Atlanta campus.”

Rev. Aaron Messner

Since 2013, Rev. Messner has served as senior minister of Westminster Presbyterian Church in Atlanta. Prior to moving to Atlanta, he had the privilege of serving as a seminary intern at the historic Tenth Presbyterian Church in Philadelphia, Pennsylvania, where he worked with the church’s outreach ministry to the homeless. After graduation, Rev. Messner was called to be a pastor at Tenth Presbyterian Church and preached extensively in their evening worship services. Five years later, he was called to work as College Chaplain and a member of the faculty at Covenant College in Lookout Mountain, Georgia, where he served for almost six years.

Rev. Messner has had the opportunity to sit under the ministries of a number of high-profile preachers in his lifetime, men like Philip Ryken and R. Kent Hughes. He has also lectured around the world on the topic of expositional preaching in conjunction with The Charles Simeon Trust. He earned his B.A. and MA from Wheaton College and his MDiv from Princeton Theological Seminary. Aaron and his wife Nancy have five children.

“For many years I have been blessed to be a recipient of the faithful ministry of RTS students, faculty, and alumni, said Rev. Messner. “It is a great honor to join the RTS family as an adjunct professor and to be able to add a humble contribution to this ministry.”

RTS Atlanta

RTS Atlanta is a growing campus located on eight beautiful acres just outside of the Perimeter in south Marietta. The campus has been training pastors, campus ministers, missionaries, educators, and church leaders in the Atlanta area for more than 20 years. They currently have around 200 students who are studying for the Master of Divinity degree, the Master of Arts degree (in Religion, Biblical Studies, or Theological Studies), and a variety of other certificate and course offerings.

RTS Atlanta is also home to the Alonzo and Althea Edmiston Center for the Study of the Bible & Ethnicity (ECSBE), which seeks to foster an appreciation for the histories and cultures of people groups that are outside of the dominant culture and, in doing so, to provide additional training for church leaders who especially want to minister in multi-ethnic, cross-cultural, and foreign missions contexts. To find out more about RTS Atlanta or the Edmiston Center, go to or call 770-952-8884.