Define, compare and contrast to the four branches of theology: Historical theology, Systematic theology, Biblical theology and Practical theology. Are there any dangers one should avoid when working within one of these branches? With an explanation of the difference(s) between progressive revelation and Inscripturated revelation..

Biblical Theology encompasses exegesis, the theological affirmations of Scripture, and the necessary implications of those affirmations. It studies how the whole Bible progresses, integrates, and climaxes in Christ. It is a way of analyzing and synthesizing the Bible that makes organic, salvation-historical connections with the whole canon on its own terms, especially regarding how the Old and New Testaments integrate and climax in Christ. Biblical theology is concerned with discerning, tracing, and describing the progress of divine revelation throughout the canon from its earliest to its latest expression. It logically precedes systematics and is the bridge between exegesis and systematics.

Systematic Theology utilizes all the data of biblical theology both to generate an orderly topical account of Scripture’s teaching upon God, man, sin, salvation, etc., and to provide answers to contemporary issues in theology, ethics, theodicy, and so on. Systematic theology is concerned with viewing and articulate biblical truth in terms of the complete canonical witness without particular concern for the developmental process at work to create its final shape. It is the more synthetic of the disciplines and aims at a unified result.

Historical Theology traces the history of the interpretation of Scripture and of theological formulations from their earliest stages through the modern period.

Practical Theology seeks to apply theological truth to all of life, particularly the life and work of believers as the body of Christ. Practical theology should naturally flow out of the other theological disciplines: exegesis, biblical theology, historical theology, and systematic theology. Practical theology applies those disciplines to help people glorify God by living wisely with a biblical worldview.

It is dangerous, while doing an effort to distinguish between biblical, systematic, historical, and practical theology, to pit one against the other as though they were at odds, with one or the other being superior. For example, biblical and systematic theology are simply two ways of viewing and expressing the same body of revelation. Yet much harm has been done by an inability to perceive their respective natures, priorities, and relationships. Some might propose that we simply proceed in a straight line, from biblical theology to historical theology to systematic theology to practical theology. But that does not work. You cannot do any one of the four theological disciplines without the other three influencing you to some degree—whether consciously or not.

Integrating the four domains of theology is the result of thinking (1) biblically, not only in terms of specific relevant texts, but also in terms of the comprehensive biblical storyline (the biblical metanarrative); (2) systematically in recognizing the theological entailments and implications of the biblical text and their relations to truths discovered in other fields of study; (3) historically with an eye to the history of interpretation, theological formulation, and practical application; and (4) practically in applying truth to one’s own life and the life of the church.

Progressive revelation is the teaching that God has revealed Himself and His will through the Scriptures with increasing clarity as more and more of the Scriptures were written. In other words, the later the writing, the more information is given. Therefore, God reveals knowledge in a progressive and increasing manner throughout the Bible from the earliest time to later time. 

Inscripturated revelation is God revealing many things before they were written down, and the first occurrence of something in Scripture may be long after its revelation in history. For example, the first we hear that God told Enoch about his coming in fire and judgment with holy angels are in the book of Jude, millennia after the actual revelation happened. Therefore, one cannot conclude that the “first mention” of a theological idea in Scripture is/was the first time that information was revealed.