It is interesting that your last classification of Theology is listed as last. The term “Theology” is a Greek word which means “The Study of God”, a theistic deity and in the theological community pacifically the Hebrew God revealed only through the Hebrew and Greek Scriptures. It was not until the 17^th century that Theology evolved to include the study of gods and religion in general.

In the beginning of creation, God spoke directly with mankind and because man became distant from God, God chose to communicate about himself in writings at God's direction. These writings are what we call revelation from God. Within Theology there are various study methods used to try to understand the content of these writings or what is now referenced as the Scriptures or the Bible, and how these writings, collectively, all relate to one subject matter – God the creator. Thus, we have Systematic Theology, Biblical Theology, Dogmatic Theology, Covenant Theology, Dispensational Theology and so on, as systems of study about one God.

Parallel to these methods of study comes the foundational studies in Biblical Hermeneutics and Upper and Lower Criticism. In the end, what you reference as “Revelational Theology” was once the only kind of theology understood in the world. If you go back to Aristotle you would find this topic translated into the philosophical discipline of Metaphysics of which my book “Made in the Image of God” focuses on.