Systematic theology, then, inevitably involves theological construction and doctrinal formulation, grounded in biblical theology and done in light of historical theology, but which also involves interacting with all areas of life – history, science, psychology, ethics, and so on. In so doing, systematic theology leads to worldview formation as we seek to set the biblical-theological framework of Scripture over against all other worldviews and learn “to think God’s thoughts after him,” even in areas that the Bible does not directly address.
In this important way, systematic theology presents a well-thought-out worldview, over against all of its competitors, as it seeks to apply biblical truth to every domain of our existence. As a discipline, systematic theology is also critical in seeking to evaluate ideas within and outside of the church.
– Stephen Wellum, Kingdom Through Covenant, 35.