Biblical study focuses on how the 66 books in the Bible can be approached, how to read the variety of texts in each book, when the texts were written, who were the writers, who were the implied readers, what the aim/s of each text, if the text contains a revelation of God, then what is the meaning of the revelation for the readers at that time, and finally what is the meaning of the text for the readers today. Christians have admitted that Biblical study or the Bible itself contains the word of God. It is the spiritual and moral source of Christians over centuries. They also agree that the Bible contains testimonies of the believers about what God has created and how the believers give their responses to God's creation.
Church history is the field of study in Christian theology in which students learn about the birth and the development of the church over time. This study focuses on the topics: the church in the first century, church in the middle ages, church in modern world, and finally church in post modern world. Christians believe that God has sent His church into the world and He guides his people to be able to proclaim the word of God to the people in the world. Christians believe that God walks together with his people in various contexts of life.
Systematic theology is one field of theological study aims to systematize the basic Christian doctrines such asa of God (theology in the strictest sense), Christology (the doctrine of the person of Christ), soteriology (the doctrine of salvation), anthropology (the doctrine of humanity), pneumatology (the doctrine of the Holy Spirit), eschatology (the doctrine of the “last things” or the end of time), and ecclesiology (the doctrine of the church).
The last branch is the practical theology. Apart from the first three branches thereof, practical theology focuses on how the word of God can be explained in practical ways so that people be able to know, believe, and practice the word of God in their daily life. The last division has been distributed into three parts, those are pastoral counseling (learning about how to solve people's problems both individually and communally), homiletic (learning about how to bring the word of God to people using verbal language), and liturgy (learning about how to teach people to surrender themselves to God. The Protestant Reformation in the 16th century marked a return to the Bible and a more practical, ethical, and less speculative tone in theology, and therefore an attempt to reduce the role of philosophy in theological work. German theologian Martin Luther, who initiated the Reformation, was not a systematic theologian, but the new teaching was presented by his colleague Melanchthon in his Loci Communes Rerum Theologicarum (1521). The greatest Reformation theologian was John Calvin, whose Institutes of the Christian Religion (1536) remains the classic of Reformed systematic theology. Calvin stressed on the sovereignty of God to the point of constructing a doctrine of strict predestination, but he tried to base all his teachings on the Bible.
In conclusion, Christian theology is the study not only of the Bible but also church history, systematic theology, and practical theology with their sub-divisions.***