The study of Theology is the study of God and the Bible. Students of theology are using information available to them to better understand who God is, given the Bible’s assertion that the character of God never changes (Numbers 23:19). For example, using information provided in the Bible, we know that God is the source of all goodness, that he hates evil, that He is actively working to best bring about the salvation of the universe, that God is one yet three through the Holy Trinity (God, Jesus, and the Holy Spirit), and some attributes of the three Trinity members.
The source of theology is informed interpretation of God’s revelation to us from the Bible. To accurately practice theology, we must first apply exegesis, which is the method of using the context we have at our disposal to see what the Bible is saying. Taking the Bible out of context without attempting to locate its true meaning is the source of many of today’s accusations against the reliability of the Bible.
Theology has several disciplines in the same way that biology, for example, has several different areas such as biochemistry, evolutionary biology, and microbiology, and people may specialize in certain areas. Descriptions of a few of those areas follows.
Systematic theology is a branch of theology that attempts to draw out systematic teachings from the Bible. For example, the Bible mentions anger (or closely related terms like angry, angered, etc.) in 267 verses. Taking into account that God does not contradict Himself, systematic theology then proceeds to analyze all those sayings. Good systematic theology is not quick to judge God’s view on a topic based on a single verse, but on the whole of what the Bible says about it. For example, anger appears to be condemned in some verses (Ephesians 4:31) but allowed in certain scenarios in others (Ephesians 4:26). Rather than call the writer a quack, the theologian examines the original language, the meaning, the context, and the purpose of those statements, as well as all the other sayings about anger in the Bible, to find out where the line is (by the way, for this example, theology states that righteous anger, or anger against the things that go against God, is not condemnable as long as it does not lead to sin, while human anger that results in violence, misdirected rage, or the like is always sinful).
Apologetics is the application of theology to preserve the truthfulness of Christianity when talking with others. For example, someone explaining to others how the biblical view of the world makes more sense than competing views is practicing apologetics. For more, see our introductory article to Apologetics.
Historical theology is the study of how theology has evolved throughout the ages. Over time, new ideas have emerged, but there is still value in learning what our ancestors thought of the same topics we study today. Learning history can also shed some light on cultural thought patterns of today. Many times objections to Christianity that are labeled as new have in fact existed for quite a while, have already been debunked, and just given a modern spin.
Moral theology examines the profound impact the Bible has on Christian morals. For example, Christianity teaches that all human life has innate value as we were all made in God’s image, and this innate value is not increased or diminished on the basis of sex, race, age, or sinfulness.
In addition to the disciplines above, theology can focus on specific topics such as the Bible, Jesus, creation, or salvation. So, perhaps one may be a historical theologian who focuses primarily on the theology of sin. No matter what form it comes in, theology is an indispensable area of study for Christians, as it is the process by which we can learn about God in order to build a deep personal relationship with Him.
The Biblical Doctrine: An Overview section of articles in the ESV Study Bible. In particular, the True Theology: Knowing and Loving God sub-section was helpful in forming this article, but the entire Biblical Doctrine section will be of use to anyone wanting to know more about theology in general or one of the major specific topics.