Biblical Theology in the tradition of Geerhardus Vos approaches the Bible as an organic drama of God's unfolding revelation through history. In distinction from doctrinal or systematic theology, biblical theology follows the progressively unfolding revelation of God's words and deeds through history. This linear aspect of revelation unites each revelatory event and proclamation both retrospectively and prospectively. Vos described the organic continuation of revelation in history as a flower expanding from bud to blossom. The blossom is retrospectively united to the bud; the bud is prospectively united to the blossom. One of the tasks/privileges of the interpreter of Scripture is to draw out these organic prospective and retrospective relationships. At the center of this organic unity is the person and work of our Savior, Jesus Christ. Even as our Risen Lord related all of Scripture retrospectively and prospectively to himself (Luke 24:27), so Reformed biblical theology is preeminently Christocentric. We seek to display Christ in Scripture from Genesis to Revelation.
But Vos also realized that a mere linear approach to biblical theology that was typological only would be a one-dimensional hermeneutic. For Vos, the Scriptures displayed a drama more wonderful than the mere linear. A mere horizontal hermeneutic was inadequate to the drama of God's entrance into history. Hence, Vos declared that a genuine Biblical hermeneutic was two dimensional -- vertical and horizontal. Intersecting the horizontal at every point in the history of salvation was the vertical. God spoke into history; God acted in history; God was incarnated in history. Vos described this vertical interface with history as the eschatological penetration of the history of redemption. In fact, Vos approached Scripture from the standpoint of the priority of the eschatological. Overarching the entire history of redemption was the eschatological arena. Every revelation of God in history was an invitation for the creature to possess the arena of the Eschatological/heavenly. This would only be accomplished through the saving work of the Son, Jesus Christ. Hence, Christ was eschatologically revealed throughout the history of redemption as the promised seed of the woman, seed of Abraham, seed of Jesse, etc. Even as God and man met in Jesus Christ, so the eschatological and the linear met at every point of God's special revelation.
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