B. B. Warfield (1851–1921) is known as one of America’s leading theologians. He served as professor of theology at Princeton Seminary from 1887 to 1921.

Sinclair B. Ferguson (PhD, University of Aberdeen) is Chancellor’s Professor of Systematic Theology at Reformed Theological Seminary and the former senior minister of the First Presbyterian Church in Columbia, South Carolina. He is the author of several books, including By Grace Alone and Lessons from the Upper Room. Sinclair and his wife, Dorothy, have four grown children.