R.C. Sproul (1939-2017) was founder Ligonier Ministries, an international Christian discipleship organization located near Orlando, Florida. He was also copastor of Saint Andrew's Chapel in Sanford, Florida, first president of Reformation Bible College, and executive editor of Tabletalk magazine. His radio program, Renewing Your Mind, is still broadcast daily on hundreds of radio stations around the world and can also be heard online.Sproul contributed dozens of articles to national evangelical publications, spoke at conferences, churches, and schools around the world, and wrote more than one hundred books, including The Holiness of God, Chosen by God, and Everyone's a Theologian. He also served as general editor of the Reformation Study Bible.

J. I. Packer is regarded as one of the most influential evangelicals in North America. He is Board of Governors' Professor of Theology at Regent College in Vancouver, British Columbia, and his writings include books such as Knowing God, A Quest for Godliness, Growing in Christ (Crossway) and Rediscovering Holiness. He has preached and lectured widely in Great Britain and North America and served as general editor of the English Standard Version of the Bible published in 2001, and theological editor of the Study Bible version. In 2014, Packer was named Author of the Year by the Association of Logos Bookstores. He is a frequent contributor to and an executive editor of Christianity Today and has written numerous articles published in journals such as Churchman, SouthWestern Journal, Reformation Revival Journal and Touchstone. He received a BA, MA and PhD from Oxford University.