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An Introduction to Systematic Theology

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An introduction to Systematic Theology

Theology means ‘words about God’; it is the study of God or anything related to God. All Christians talk about God, making all of us theologians. Of course, that does not necessarily make us good theologians. Being a good theologian requires study and effort, a task many are unwilling to make. But it is a beneficial task. The better I know God, and what he is doing in creation, including with me, the more effective I can be in serving him.

Systematic theology is a specific branch of theology that examines all of the church’s doctrines and systematizes them, ensuring that they all fit well together in harmony. Who and what we understand God to be will affect pretty much every other doctrine we have. What we understand about sin will impact what we believe about the work of Christ and salvation. Many of our doctrines are like this, so a good understanding of one requires a broader understanding of many others. Systematic Theology studies all the major doctrines in a framework that will knit them together in a cohesive and coherent whole.

Why Study Theology

There are many things that the systematic study of theology can do for you. The five-letter acronym PEACE can help in remembering at least of few of these reasons.


This word is defined as “a strong verbal or written attack on someone or something.” In this case, it is used in the sense of combating false doctrine. False doctrine is rampant today, just as it has been throughout the history of Christianity. Effective theology can help you to identify and then counter the false doctrines of our day. Too often, those doctrines sound good on the surface, and they can deceive those who are unfamiliar with the teachings of the Bible.


Exegete means ‘to expound or interpret‘, especially the Scriptures. Exegesis is useful for a teacher. But it is just as useful for an individual seeking to understand or explain a specific position or doctrine.


Apologetics is defined as ‘reasoned arguments or writings in justification of something, typically a theory or religious doctrine‘. Frequently this term is used in the sense of giving a defense of your faith to outsiders. But it can also be useful for believers who have questions about their own faith or who are experiencing periods of doubt.


This word means to ‘instruct in the principles of the Christian religion by means of question and answer, typically by using a catechism‘. Think of it as providing training to new believers, providing them with the basics of the faith.


Having a good understanding of Christian truth makes you a more effective evangelist. It helps you to more fully understand the condition of the one you are witnessing to, as well as the provision God has made to redeem them.

Theological study is useful for your own development, edification, and understanding of the God who made us and is still working in our lives. It is useful in guiding you to help other believers in their own personal growth. And it is useful as you introduce others to the gospel.

Sources for the Study of Theology

There are many sources that people use for developing their theology, some good, some not so good, and some that are downright terrible. The Wesleyan Quadrilateral describes four of these sources: Scripture, reason, tradition, and experience. While there are other sources that some use, I believe that this one does a good job of grouping our primary sources.


It should be obvious that the Bible is our primary source for theology. After all, what can be a better guide to knowing about God and his working than the text he has given to us? The Scripture is inspired by God and is useful to us in our life with Christ, containing all that we need to be mature and complete believers.

However, the Bible is not a systematic theology book. It contains theology within its pages, but not necessarily in the format we would like to have. The Bible is the story of God’s interaction with humanity, and it is sometimes a messy story involving cultures that are foreign to us. Great care needs to be taken when deriving our theology from the Bible to separate the content of the theology from the context of the culture in which it was written.

I cannot overemphasize the importance of the Bible in the development of our theology. While it can be challenging to understand sometimes, it must be the bedrock that our theology rests upon. If our tradition, reason, or experience appear to be at odds with the Bible, we should give precedence to the Bible. It may be that we have misunderstood what the Bible is teaching us. But it will always be true.


The Wesleyan Quadrilateral does not use tradition to refer to our practices within our local church or denomination. Instead, it refers to the teachings of the church. The Bible does not directly contain the formulation of the Trinity that the church holds to today. The doctrine of the Trinity was developed over a long period of time to express truths that are contained within the Scriptures. The doctrine of the Trinity comes to us from tradition. The dual nature of Christ, the fundamental role of the atonement, soteriology, various views of eschatology, and other doctrines that sometimes divide us are largely a product of tradition.

Tradition is not bad; it represents the labors of many godly men through the ages trying to understand how God is working. But it is not infallible and is of lesser importance than Scripture.


In some circles, reason and faith are seen as opponents in the ring, ever at odds with each other. But that is unfortunate. God has given us minds and instructed us to use them (Mark 12:30). The development of our tradition was by the application of rational thought to the Scriptures. It is appropriate for us today to continue to apply our minds to the study of Scripture and our search for knowledge and understanding of God.

If your theology is based solely on what others teach you, then you stand on pretty shaky ground. When difficulties or challenges to your faith come along, you may find that your theology, if developed without rational thought on your part, may well not sustain you. But, the danger with using our minds is that we need to ensure that our thoughts are well-grounded in the Word.


Experience may not be the best guide to our theology, but it is one from which we cannot separate ourselves. My experiences shape who I am and how I think. But my experience with God, as well as the experience of others in their interactions with God, can help me to gain a better perspective on him. Of the four, this is the one that I trust least, but it is undeniably a part of how I do theology.

The Holy Spirit

The Holy Spirit is not included in the Wesleyan Quadrilateral, yet I believe that we cannot do good theology without the assistance of the Holy Spirit. In 1 Corinthians 2:10-16, Paul expresses that no one knows the thoughts of God except for the Spirit of God, the Holy Spirit. And God has given us his Spirit to help us to know him. We will not be able to know God apart from his Spirit’s help. Just be sure that you do not confuse your own rational thought process with the leading of the Holy Spirit. The Spirit will work within our thoughts, but our thoughts may also operate without, or contrary to, the Spirit.

How to do Theology

If you are interested in developing good theology, and systematic theology in particular, there are a number of things to be aware of. The steps below can assist you in your development.

Be Complete

There is a danger in developing your theology independently of the Scripture, and then turning to the Bible to find support for your positions. This is a surefire way to develop bad theology. You need first to determine what all of Scripture has to say about a particular doctrine, as well as the relevant church tradition. You may not always find that you can reconcile all of the teachings about a topic. But you should strive to form doctrines that best support the majority of the texts.

Separate Content from Context

It is important to remember that the Bible was written by and for a culture that is very different from that of the 21st-century United States. The place of women and slaves is quite different now. The government and economy of the biblical period are quite foreign to us today. Education, technology, and healthcare are dramatically improved today. It is natural for us to read the Bible as if it were specifically written for us today. But it was not. That does not reduce the value of Scripture for us. But it does mean that we need to take that cultural setting into account. The content, or message, of the Bible, is timeless. The context, or culture, of the Bible, is not. Distinguishing between the two is an important task in developing your theology.

Update the Context

Once you have separated the content and the context, you should apply that content to your own culture; or to the culture that you are trying to reach. Jesus as the good shepherd is meaningful to a pastoral culture. But it can leave modern city dwellers somewhat in the dark. Can you update the message of a savior who cares and provides for his people with more modern imagery? The prescientific view of creation expressed in Genesis is challenging to a scientifically oriented culture. Yet the content, that God created all that is, remains as true today as it was then.

Ensure Coherency

I know people who will remark after a tragedy in their lives that it was meant to be, implying that God controls everything that happens. And yet those same people believe that they actually have some control over their lives, making real choices. But the two positions seem to be at odds with each other. God is omniscient and omnipotent, creating the universe the way he wanted it to be, yet many view creation as broken and God as scrambling to fix it. We are going to have paradoxes in our theology, like the teaching that Jesus is fully God and fully human. We are finite and trying to understand the infinite. But our theology should be as consistent and coherent as we can make it. We should not say that God is in full control and that he is not in full control.

A Warning

There are two distinct ways of ‘doing’ theology. The first is to simply study some authority on the subject and adopt their position. There are many good sources for theology, and most of them are in general agreement on most positions. Erickson, Grudem, Geisler, Odem, and others have produced massive volumes on systematic theology and are highly recommended, especially Erickson. But I would encourage you not to take that approach. Use these books as resources in your study, but don’t just accept what they have to say.

The second approach is much more challenging and more dangerous, but ultimately more rewarding. Read the relevant passages in the Bible. Study the works of other theologians. And think. Allow the Holy Spirit to guide you. Ask questions, and don’t be afraid of the answers. The challenge to this approach is that it is much more work than simply reading and accepting what someone else has said. The danger is that you may not come to the same conclusions as the authors of the books you read or of your teachers. Just be sure that your theology is solidly grounded in the Scriptures and not in some other source. And the reward? That your theology will become more deeply ingrained in you, that it will be yours rather than someone else’s.

This Guide

That, in a sense, is what the articles in this guide are. They are the product of years of study, asking questions, and exploring responses. In many respects, it is very similar to what you would find in a much larger systematic theology text, but not always. There is no guarantee that it is all correct; most likely, it is not. But it is what I feel I have been led to. Please, as you read this, do not just accept or reject it. Allow God’s Spirit to lead you into the truth. It is a glorious journey. Whether you agree with me or not, study the Scriptures because, in them, you will find the truth.

The Framework

Most systematic theologies start with either God or the Bible. You might start with God because, without him, the Bible has no value. You might start with the Bible because, without it, we can know little about God. It’s kind of a chicken and egg thing. I have opted for a different approach. After this introduction to systematic theology, I will look at what can be known about God apart from the Bible. Next, is what we can know about the Bible. This assumes that God would want us to know more about himself than can be ascertained by our own rational thoughts. And it sees the Bible as the record of this self-revelation. And then, we will study God as described in the Bible.

From there, we will follow a more traditional sequence, each doctrine building on the ones that came before. Not every doctrine of Christianity will be covered, but the major topics will. The rest of them can be easily added on your own.

  • An Introduction to Systematic Theology (5/21/2021) - This is an introduction to the topic of systematic theology. It will be providing some general guidelines for a systematic study of theology.
  • The God of General Revelation: What Creation Tells Us (5/28/2021) - Does God exist? How can we know that? And if he does exist, what is he like? What can we learn about God apart from the Bible?
  • The Doctrine of the Bible (6/12/2021) - From the human perspective, the Bible is a diverse collection of literature written over a long period of time. From a divine perspective, it is the authoritative guide to faith and practice.
  • The Doctrine of the Nature of God (12/30/2017) - What is the nature of God? This post is a quick look at the attributes of God, the Trinity, his will, and some commonly raised questions.
  • The Doctrine of the Work of God (1/7/2018) - What is the work of God? It involves creation of the cosmos as well as providence, the sustaining and governance of his creation.
  • The Doctrine of Humanity (3/2/2017) - Who are we as humans? Where did we come from? Why are we here? The doctrine of humanity provides answers to those questions.
  • The Doctrine of Sin (3/19/2018) - The doctrine of sin is one of the foundational truths of the Christian faith. It describes an aspect of our nature that is opposed to God.
  • The Doctrine of the Nature of Jesus Christ (4/12/2018) - The nature of Jesus . . . He is the second person of the Trinity. And he is both fully God and fully man, perfectly united into one person.
  • The Doctrine of the Work of Jesus Christ (4/29/2018) - The primary work of Jesus is offering himself as an atoning sacrifice for our sins. Jesus' atonement for us is essential for our salvation.
  • The Doctrine of the Holy Spirit (6/4/2018) - The Holy Spirit, the 3rd person of the Trinity, brings conviction of sin, enables life as a believer, and equips for service in the Kingdom.
  • The Doctrine of Salvation (6/27/2018) - The doctrine of salvation encompasses our initial salvation experience, our ongoing walk with Christ, and our final deliverance.
  • The Doctrine of the Church (7/29/2018) - What is the church? What is it's purpose? Questions about government, baptism and Lord's Supper. These are topics addressed by the doctrine of the church.
  • The Doctrine of Last Things (9/15/2018) - The doctrine of last things includes the global events preceding Christ's return, as well as the more personal aspects; what happens to me in the end.

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Ed Jarrett

Just an old clay jar that God continues to see fit to use in his kingdom's work. I am retired, married with 2 children, and 4 grandchildren. I have followed Jesus for many years. And I love to share what He has given me from His word.

A Note to Readers

The views expressed here are solely mine and do not necessarily reflect those of any other person, group, or organization. While I believe they reflect the teachings of the Bible, I am a fallible human and subject to misunderstanding. Please feel free to leave any comments or questions about this post in the comments section below. I am always interested in your feedback.

8 thoughts on “An Introduction to Systematic Theology”

  1. Hi
    I’m basically a teacher who is currently teaching Systematic Theology.
    I’m using Grudem. But your website has been a HUGE help to me.
    God bless you richly for this resource. And may he grant you divine wisdom to develop many more faith-building resources!
    Thank you!

    • Thanks for sharing that. Much of the systematic theology posts on this site came out of my own teaching of the subject. I used them as handouts for my students. I found Erickson’s “Systematic Theology” to be the most helpful resource I found.

  2. I find it somewhat intriguing that you so candidly acknowledge that the trinity is driven more by tradition than Scripture. Being a non-trinitarian follower of Christ, ie he never existed in any form, beyond his Father’s mind and aspiration, I find it intriguing that followers of Christ hang on so tightly to the trinity doctrine, it totally baffles me. The trinity adds nothing to the work of Christ, beyond confusion. Even today the Jews only acknowledge one God, it is foreign to their understanding of who God is. There are so many signs that a world in moral decline is heralding our Lord’s return. The promises made to Abraham in Genesis 12, is the mould that history has been poured into.

    • You have misunderstood what I said if you think I ‘acknowledge’ that the doctrine of the Trinity is more driven by tradition that Scripture. It is true that the doctrine of the Trinity, as formulated in the early creeds, is not explicitly taught in the Scripture. But that doctrine is clearly based on what the Scripture has to say about the Father, the Son and the Spirit. Contrary to your opinion, it is not a man-made doctrine.

      I am not sure what you mean by “he never existed in any form, beyond his Father’s mind and aspiration”. That sounds like you do not believe that Jesus was every anything beyond a thought in the Father’s mind. And if that is the case, it is hard to picture you considering yourself a Christ follower.

      What does the Trinity add to the work of Christ? Without it there is no incarnation and no perfect atoning sacrifice. If Christ is just a figment of God’s imagination, or juat a human, then what did his death on the cross accomplish?


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