Systematic Theology (https://www.thegospelcoalition.org/essay/systematic-theology/) is what we usually think of when we hear the words theology and doctrine. The different section, usually around ten, with statements and scriptural support for what the Bible is (bibliology), who God is (theology proper), who Jesus is (Christology), who the Holy Spirit is (Pneumatology), who man is (anthropology), and so on.
Biblical Theology (www.thegospelcoalition.org/essay/biblical-theology) is examining theology as it is revealed in the Bible - progressive revelation.
Historical Theology (www.thegospelcoalition.org/essay/historical-theology/) is watching the development of theology throughout church history.
Finally,,Biographical Theology is looking how men and women lived their lives because of what they believed the Bible says about God.
Each of these theologies need to be rooted in Scripture. What does the Bible truly say about God? Not what did a person say about God? or What did a specific time in history say about God?
The Hidden Smile of God click for a free pdf of the book) is about the lives of John Bunyan, William Cowper, and David Brainerd.
In today's class (12/11/22), we look at the life of John Bunyan.