Dr. Clark was educated at the University of Nebraska (BA), Westminster Seminary California (MDiv), and St Anne’s College, Oxford University (DPhil). He was a minister in the Reformed Church in the United States (1988–1998) and has been a minister in the United Reformed Churches in North America since 1998.

He is Professor of Church History and Historical Theology. He has taught at the undergraduate and graduate level since 1997. In that time he has also served as Academic Dean (1997–2000) and the host of the Office Hours broadcast (since 2009). He has taught at Wheaton College, Reformed Theological Seminary, Jackson, Concordia University, Irvine, and Westminster Seminary California.