Joel R. Beeke (PhD, Westminster Seminary) is president and professor of systematic theology and homiletics at Puritan Reformed Theological Seminary; a pastor of the Heritage Reformed Congregation in Grand Rapids, Michigan; editor of Banner of Sovereign Grace Truth; editorial director of Reformation Heritage Books; and a prolific author.

Diana Kleyn is a member of the Heritage Netherlands Reformed Congregation in Grand Rapids, Michigan. She is the mother of three children, and has a heart for helping children understand and embrace the truths of God's Word. She writes monthly for the children's section in The Banner of Sovereign Grace Truth magazine, and is co-author with Joel R. Beeke of the series Building on the Rock.