Biblical theology is the study of the doctrines of the Bible, arranged according to their chronology and historical background. In contrast to systematic theology, which categorizes doctrine according to specific topics, biblical theology shows the unfolding of God’s revelation as it progressed through history. Biblical theology may seek to isolate and express the theological teachings of a specific portion of Scripture, such as the theology of the Pentateuch (first five books of the Old Testament) or the theology contained within John’s writings, etc. Or it may focus on a particular period of time, such as the theology of the unified kingdom years. Another branch of biblical theology may study a particular motif or theme in the Bible: a study of “the remnant,” for example, might search out how that motif is introduced and developed throughout Scripture.
Many credit J. P. Gabler, a German biblical scholar, with beginning the field of biblical theology. As he was being inaugurated to a professorship in 1787, Gabler called for a sharp distinction between dogmatic (systematic or doctrinal) theology and biblical theology. For Gabler, biblical theology must be strictly a historical study of what was believed and taught in the various periods of biblical history, independent of modern denominational, doctrinal, philosophical, or cultural considerations. In general, the principles that Gabler espoused were correct, and he influenced the development of biblical theology for many years to come.
However, it should be noted that there is no such thing as a study of the Bible with complete objectivity. Every interpreter brings certain presuppositions to the task. These biases have considerable influence upon the process of interpreting the Scriptures. As a result, the field of biblical theology is checkered with every imaginable opinion and variation of what the Bible teaches. Biblical theology is utterly dependent upon the hermeneutics of the theologian. The methods employed in interpreting Scripture are crucially important to biblical theology. One’s biblical theology can be no better than the methods he uses to interpret Scripture.
Here is a basic difference between systematic and biblical theology: systematic theology asks, “What does the Bible as a whole say about angels?” and then examines every passage that concerns angelic beings, draws conclusions, and organizes all the information into a body of truth called “angelology.” The final product is, from Genesis to Revelation, the totality of God’s revealed truth on the subject.
Biblical theology asks, “How did our understanding of angels develop throughout biblical history?” and then starts with the Pentateuch’s teaching about angels and traces God’s progressive revelation of these beings throughout Scripture. Along the way, the biblical theologian draws conclusions about how people’s thinking about angels may have changed as more and more truth was revealed. The conclusion of such a study is, of course, an understanding of what the Bible has to say about angels, but it also places that knowledge in the context of the “bigger picture” of God’s whole revelation. Biblical theology helps us see the Bible as a unified whole, rather than as a collection of unrelated doctrinal points.