Geoff Chang serves as an assistant professor of church history and historical theology and is also the curator of the Spurgeon Library at Midwestern Baptist Theological Seminary. You can follow him on Twitter at @geoffchang.
Jonathan (@JonathanLeeman) edits the 9Marks series of books as well as the 9Marks Journal. He is also the author of several books on the church. Since his call to ministry, Jonathan has earned a master of divinity from Southern Seminary and a Ph.D. in Ecclesiology from the University of Wales. He lives with his wife and four daughters in Cheverly, Maryland, where he is an elder at Cheverly Baptist Church.
Matt Smethurst serves as managing editor for The Gospel Coalition. He and his wife, Maghan, have three children and live in Louisville, Kentucky, where he serves as an elder at Third Avenue Baptist Church. You can find him on Twitter at @MattSmethurst.