“Perhaps no single factor is more detrimental to Biblical exposition in our day than a widespread failure to recognize that the Bible is a unity and in order to be adequately interpreted must be treated as such. In many circles this unity is lost sight of in a tendency to emphasize the diversity of the content of the Bible.
“In other circles the Old Testament and New Testament are studies apart from one another, with little or no attention paid to their close interrelation. Their theologies are frequently treated separated and in many instances the New Testament is refused its legitimate role as a commentary on the Old Testament. Schools and theological seminaries customarily allocate the Old and New Testament into different departments, a practice doubtless necessary, but fraught with the gravest peril to expository preaching, when the essential unity of the Bible is not kept constantly in mind” (Merrill F. Unger, Principles of Expository Preaching [Grand Rapids: Zondervan, 1955], 156). I might add that one of the values of having a Bible Exposition department in a Bible college or seminary is the cross-Testament, cross-disciplinary nature of the department. One reason that I chose Bible Exposition as a discipline was its crossroads-like nature where Old and New Testaments, preaching/teaching, and biblical theology intersect.