What is Systematic Theology and Why Does it Matter?

An Introduction to Systematic Theology

Thanks for subscribing, this is the second in a series on Biblical, Systematic, and Historical theology. In summary, these are simply defined as:

Biblical Theology = “What does the Bible say?”
Systematic Theology = “What does the Bible say about…?”
Historical Theology = “What has the Church / have Christians historically believed about…?”

More Than a Book

“Yeah, I’ve heard of Systematic Theology, I have the book at home somewhere.”
— Almost everyone I’ve spoken to about Systematic Theology

This is the sentence which convinced me to write this series. I don’t know how many times I’ve heard it said—it’s certainly in the high double-digits range—but when I heard it again recently my heart broke a little. The misconception that Systematic Theology is just a book (probably a blue book written by a guy called Wayne) is an understandable one, as it’s the only one most people have seen, even if most people, following the sentence above, say something along the lines of, “Oh, I haven’t read it though,” or “I mean, it isn’t really meant to be read, right?”

My thoughts about that particular volume aside, this saddens me even more than the first response. You would assume that a book which commands the sole attention of someone’s mind when they think of Systematic Theology (ST) would at least be widely read, but from my experience, this isn’t the case. It may be that in previous generations when questions about difficult subjects arose the book would be pulled from the shelf in order to help answer them, but in the digital age, why not just open one’s phone, type the question into Google, and click on the first link¹?

If so many people misunderstand what ST is, and even more don’t seem to need to understand ST in order to find the answers they want, why even raise the issue? Problem solved!

Not quite.

There’s a famous scene from the TV show Friends in which disaster strikes when Rachel tries to make an English dessert. “It's a trifle. It's got all of these layers. First, there's a layer of ladyfingers, then a layer of jam, then custard, which I made from scratch. Raspberries, more ladyfingers. Then beef sautéed with peas and onions. Then more custard and then bananas and then I just put some whipped cream on top.” Rachel, proud as pudding, presents her creation, and when questions arise about the inclusion of the beef she replies, “You know, [British] people just put very strange things in their food.” using the example of “Mince Pies”² to prove her point. It's all very well having access to a cookbook, some food, and some utensils, but the wisdom to know how to use them, what foods go well with others, or even whether two pages might be stuck together, are beyond important when it comes to serving up something edible.

The same is true of Theology, just as Rachel’s “System of Gastronomy” erroneously allowed for odd combinations in British food, a faulty understanding of ST leaves us blind when it comes to discerning good answers to our questions from the bad.

“But as for you, teach what accords with sound doctrine”
English Standard Version, Titus 2:1

Since the early church Christians have wrestled with the practical application of this simple command. It’s all very well telling us to teach “what accords with sound doctrine,” but what does that entail? The Bible doesn’t only talk about good doctrine either, but also bad doctrine—even the doctrine of demons—but whilst all doctrine must come from a full and thorough understanding of the Bible, the Bible itself doesn’t contain a systematic list of the good and the bad; as much as we might wish that we could flip to Romans 17, and read a final, exhaustive list of do’s and dont’s.

This isn’t to say that the Bible is up to each person’s interpretation either. It would be foolish to assume that just because certain details are unclear, this allows us to place anything we like back into the Bible, and pretend it’s true because “that’s my interpretation.” The Bible is explicitly clear on most issues, and the Church, even with its many denominations, is far more united than we often think. The Apostle’s Creed, for instance, is recited in churches of various backgrounds around the world each and every Sunday, despite differences in understanding about the gifts of the Spirit, the second coming of Jesus, the nature of the Lord’s supper, we can all agree on this:

I believe in God, the Father Almighty, Creator of Heaven and earth;
and in Jesus Christ, His only Son Our Lord,
Conceived by the Holy Spirit, born of the Virgin Mary,
Suffered under Pontius Pilate, was crucified, died, and was buried.
Descended into Hell; the third day He rose again from the dead;
He ascended into Heaven, and now sits at the right hand of God, the Father almighty;
He shall come to judge the living and the dead.
I believe in the Holy Spirit, the holy catholic church³,
the communion of saints, the forgiveness of sins,
the resurrection of the body and life everlasting. Amen.

— The Apostle’s Creed

In fact, disagreeing with this creed is one of, if not the determining factor in deciding whether someone is teaching heresy. Why? Because this teaching is Biblical; by Biblical I don’t mean that this is scripture though. This isn’t a lost section of 3 Corinthians or a late teaching of Jesus, but each word was discussed, defended, and delivered to the saints by a group of trusted pastors and scholars who read, studied, and loved the Bible, and has been confessed as truth through two millennia of Church History by others who read, studied, and loved the Bible too. This Creed—this system of theology—clarifies for believers the basic truths of the faith which the Bible teaches in order to codify and simplify what might take a lifetime to fully grasp.

Systems are not good, however, in and of themselves. ST can, like Rachel’s trifle, be confusing and painful to swallow and contain elements which don’t belong. In Irenaeus’ Against Heresies, he describes the heretics’ actions by saying:

…the method which these men employ to deceive themselves [is to]… abuse the Scriptures by endeavouring to support their own system out of them.

Irenaeus of Lyons, The Apostolic Fathers with Justin Martyr and Irenaeus, 1885, 1, 329.

How can we be sure to create a good system—which we would call orthodox—and not a heretical one?

Where to Start

Before you do anything else, read the Bible. A good grasp of Biblical Theology will ground you in what’s important, and help you not be swayed by the changing tides of the culture, even the culture of the Church. Even as recently as this past month, the Church in the UK has weathered incredible storms both from without and within, but the ones who are still standing afterwards are the ones who built their house on the rock. I say this knowing that you could go and pick up, for instance, Louis Berkhof’s ST and read it through, making notes, and come out the other end with a good grasp of ST. This is a surefire way to believe like the enemy, in truth, but not in Spirit and truth. It is quite possible to know the best arguments for Calvinism, or the amillenial view of eschatology, or why the Bible calls men as elders in the Church without any love for Christ or the Bible, it is even possible to fight for “Systematic” Christian values without ever coming to faith. I’ve known of people who would openly say that they believed in Calvinism before they believed in Christ, because the logic of the system made sense to them, even if the gospel didn’t.

Start with the Bible, getting to know what the Bible says is the best way to begin learning about God and what truth looks like. Imagine for a second that you’d read every article I’d ever written, there are ninety-two on this site alone, if someone then gave you three articles and asked you to determine which one I’d written, and which ones were written by other writers/bloggers, you’d be able to make a well-informed decision; or instead imagine appearing in court as a witness and being asked to determine whether a voice recording belonged to a close friend or family member, even without knowing exactly how you’d be able to give an accurate answer because you know their voice.

There’s an old proverb which goes, “When is the best time to plant an oak tree? Twenty years ago, but the second best time is now,.” The same is true of Bible reading, you may have been a Christian twenty minutes, twenty weeks, or twenty years, and may have always struggled to find the will to dig into the scriptures. I’ve spoken to so many people who find it hard to start reading because of guilt over not having started earlier, if that’s you, start now!

As important as it is to read the Bible, it is important not to do so alone, there are theologians that preceded us in reading the Bible and have wisdom to pass on, but just as we must be sure to accept wise counsel, we must be wise about the counsel we keep. That starts by listening to a variety of voices.

Shortly before I left school London hosted the Olympics, and the whole country—to everyone’s surprise—threw itself behind athletes, causes, volunteering, and attending events; as a result, previously unknown athletes became British heroes and heroines. One of these heroines was Jessica Ennis. I distinctly remember the rising excitement after the first day of the heptathlon which saw Ennis break the record for most points scored in a single day. Ennis went on to take home the gold medal and spend the next few months appearing on chat shows, speaking to schools, and hopefully getting some rest.

When we compare Ennis’ times, however, to the other female Olympic champions in each of the sports Ennis competed in, we get these results:

Whilst Ennis stood head and shoulders above her fellow all-rounders, against athletes focussing on one particular sport, she wouldn’t have had a chance—it’s unlikely she would have even qualified for any individual event.

When building a library of books on Systematic Theology, don’t let that library be occupied by a single author. It is impossible to expect any single theologian to provide equal attention or rigour on all subjects, so rather seek out a broad range of authors who have done specific and detailed work on the subject at hand, or who have a track record of understanding and clarity about that subject. If you would like a list of recommendations, leave a comment to let me know and I’ll make sure to write an article on that in the near future.

The second step follows the first in spirit, but not in form. It is a good idea to pick up a single collection of detailed but simple answers to a wide range of questions but written by a huge host of theologians⁴. I’m not speaking in the abstract here, but about a specific set of systems which have been handed down throughout Church History. These fall under three categories; Creeds, Confessions, and Catechisms. If Church History were the British Crown jewels, these three parts of that inheritance would form the Orb, the Sceptre, and the Ring which accompany our crown of righteousness. Whilst we should certainly still value the whole vault, these are priceless. You can find these jewels freely online, or in single volumes alongside commentary, but whatever you do, make sure these are a part of your library.

Finally, whilst I don’t think any one author should command your entire understanding of ST, there are excellent volumes—or multi-volume series!—written by one or two men which I do recommend, and that will help to supplement your learning, as well as providing a full understanding not only of how to build a system, but how various elements of the system relate to one another.

They will cover subjects like the theology of salvation, the theology of the Church, what it means to be Human, the nature of the Trinity, Apologetics, how the Church ought to interact with culture, and many more areas of theology.

I won’t give an exhaustive list here, I will only suggest a few you might want to begin with, but I will say that when looking for a Systematic Theology, it is a good rule to check to see whether what followed from life of that theologian who wrote it suggests/ed that they are a saint you might want to imitate. There is wisdom in choosing volumes from those who are sadly no longer with us but don’t preclude living men and women from your libraries, just be careful to choose them well.

Here’s a short list⁵:

• R.C Sproul’s The Essentials of the Christian Faith

• Cornelius Van Til’s Introduction to Systematic Theology

• Geerhardus Vos’ Reformed Dogmatics

• Herman Bavinck’s Reformed Dogmatics

In the introduction to this series, I said that the definition of, and chief aim, of ST is the answer to the question, “What does the Bible say about…?” Whilst this is a simple definition, it tracks pretty well and distinguishes it from Biblical Theology, which asks a simpler, but deeper question, “What does the Bible say? These two questions make up two of three main parts of the theological life of the Church, alongside other smaller parts like, “What do other faiths say about God?” and “What does my culture think about God?” The third main part is Historical Theology, which asks the question, “What has the Church / have Christians historically believed about…?” and thinks about if/why/how that has bearing on our lives or our understanding of the Bible today. That will be the next part of this series, but potentially not the last. These articles have taken a birdseye view of each of these parts of the theological life of the Christian, but not at the finer details. I’d love to know if there are particular areas of theology you would like me to take a deeper look at throughout 2023. This could be about, for instance:

• Sotieriology - The Theology of Salvation

• Scripture

• The Attributes of God (Immutability, Wisdom, Righteousness, Omnipotence, etc.)

For those of you who aren’t subscribed, I already have a historical theology series ongoing which looks at the 1200 years of Church History which protestants have often left largely unread. Please do check that out, and if you found this article helpful, please do subscribe for more articles like this, and to receive the final instalment of this series in your inbox on Tuesday the 31st of January!

Finally, keep reading your Bible, keep learning from the saints who have preceded you, and who have wisdom and knowledge to impart, and most importantly, don’t neglect the scriptures in search of something more fulfilling. ST develops our doctrinal understanding but doesn't replace the Bible, we need to read the scriptures to hear the voice of the Lord and to spend time in communion with him. To prize ST over the Bible would be like neglecting to spend time with my wife to dwell upon how to love her better and to simply think about her. If I did that a chasm would grow between my imagination and my true knowledge of her.

Grace and Peace,

Adsum Try Ravenhill

1. Whilst Google is a helpful tool, it is subject to SEO, and rife with heretical views posing as orthodox views.

2. A British Christmas dessert with “Mincemeat” made from dried fruits, alcohol of some kind, and nuts.

3. Small c, read more about why that’s important here:

Judah, Judas, Jude?

4. The Westminister Catechism was debated over, and curated by 121 divines! Not to mention others who proofread the texts afterwards.

5. I may have another later in the year, but it is three volumes and I need some time to get through it.