James Grant writes:
As Christians, we are called to know our God, and one way we learn of God is through Scripture. As we read Scripture, we often read it devotionally, without making the broader connections to various doctrines and themes. Drawing the various themes of Scripture together and seeking to understand its meaning is the task of theology, and theology has several disciplines to help with this task.
Exegetical Theology: This comes from the Greek term that means “to lead out.” With this discipline, we are trying to lead meaning out of a particular passage instead of reading our meaning into the passage. As we interpret and explain the passage, we ask what it conveyed to the original audience.Normally exegesis is focused on original intent.
Biblical Theology: This discipline traces the development of the Bible along the lines of redemptive history. We could trace the development of a theme (Kingdom of God), examine the theology of a particular book (What is the theology of Genesis?) or a group of books (What is the theology of the Pentateuch?) or a particular person (What is Paul’s theology?).
Systematic Theology: This is the attempt to set forth biblical truth topic by topic and as a whole, especially in light of some of our current challenges and struggles in the church. We could ask what does the Scripture say about the kingdom and how does it influence our understanding of the relation of church and state. The main topics of systematic theology are the Doctrines of Scripture, God, Man, Christ, Salvation, the Church, and End Times.
Historical Theology: This is the study of how theologians throughout the church’s history have understood various topics and passages of Scripture. By using this discipline, we are relying upon the development of doctrine and our various traditions. As we study the Kingdom of God, we would ask this: How did Augustine understand the Kingdom of God in his classic work City of God.
Philosophical Theology: This discipline is also called natural theology. By using it, we are studying some of the concepts of theology with the tools of philosophy. This discipline provides a link between theology and secular thought. It is the study of fundamental concepts of theology with tools of philosophy, and this provides a link between theology and secular thought. An example of a question we could ask for this is, “What is a kingdom?”
Although there are more types of disciplines (Pastoral Theology, Apologetics, Christian Ethics, etc.), these are the primary disciplines for the practice of understanding Scripture. Knowledge of these different disciplines can help us in our understanding of Scripture and our walk with the Lord as we are more specific with our studies.