By Bill Murphy
“Why do I need systematic theology when I have the Bible?”
If you are like many church leaders, you have probably heard that question before. Maybe you have even asked it yourself. Let’s face it: systematic theology has gotten the reputation that it is just for academics or those who simply like to punish themselves by stuffing a 4-pound hardcover book some 1586 pages in length into a backpack to take to the park for a bit of light reading under a shade tree.
Yet, Wayne Grudem’s Systematic Theology: An Introduction to Biblical Doctrine, 2nd ed. (which actually is a 4-pound hardcover book some 1586 pages in length), is experiencing a surge in sales so dramatic we thought it was time to take a closer look at Grudem’s book, and suggest three reasons why systematic theology has become so popular these days.
1. Systematic theology is familiar.
Doubt us?
You already know the subject matter, only you do not refer to it by that name. You call it the Apostles’ Creed, the Westminster Confession of Faith, Larger Catechism, and Shorter Catechism, the Nicene Creed or the Canons of Dort.
Those are all the product of systematic theology.
Or, to put it another way, they are systematic theology in creedal form. And you probably recite them weekly in church. So, systematic theology has been part of your life since the beginning of your faith journey, but you probably did not even know it.
Another aspect of the subject that is already familiar to you is found in the way Grudem defines systematic theology:
Many different definitions have been given, but for the purposes of this book the following definition will be used: systematic theology is any study that answers the question, “What does the whole Bible teach us today?” about any given topic.
Thus, believers are familiar with the historic creeds and confessions, of the faith and they’re familiar with their Bibles.
2. Systematic theology is fun.
Wayne Grudem wrote Systematic Theology: An Introduction to Biblical Doctrine, 2nd ed., for all Christians. In the Preface to the first edition, he writes:
"I have not written this book for other teachers of theology (though I hope many of them will read it). I have written it for students—and not only for students, but also for every Christian who has a hunger to know the central doctrines of the Bible in greater depth.
This is why I have called the book An Introduction to Biblical Doctrine. I have tried to make it understandable even for Christians who have never studied theology before. I have avoided using technical terms without first explaining them. And most of the chapters can be read on their own, so that someone can begin at any chapter and grasp it without having read the earlier material."
You won’t get far into Systematic Theology before you see that Grudem’s writing style is inviting and engaging, drawing readers into each chapter, from the first page to the end. Then, almost as an added bonus, Grudem concludes his chapters with a Scripture Memory Passage, and even lyrics to a Hymn or a Contemporary Worship Song to further help his readers understand and apply what they just read.
In addition, ChurchSource offers a series of video teachings, a Systematic Theology Workbook (3-hole punched), and a six-panel laminate (also conveniently 3-hole punched) that you can keep in a binder for easy access and reference.
With so many helps available, you’ll likely come to the end of studying Systematic Theology: An Introduction to Biblical Doctrine, 2nd ed, amazed by how fun it was to learn the core doctrines of the Christian faith.
3. Systematic theology is fulfilling.
Grudem wrote his book (which has sold over 750,000 copies!) in an engaging way to give readers what they need to know to better understand their faith…and to more ably answer questions posed to them by friends, relatives, neighbors, skeptics, and atheists alike. Grudem divides his book into seven major sections, according to seven major doctrines:
What Christian couldn’t benefit from knowing more about those doctrines, especially since 1 Peter 3:15 commands us to “Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect…” How can we expect to give an answer if we haven’t earnestly studied the basics of our faith? As one professor of apologetics says, “If you want to be a good apologist, you need to study systematic theology and hermeneutics.” In other words, it is much easier to share the Gospel with others if we know what we are talking about. Thus, studying systematic theology will not only prepare us to give answers, it will also build us up in the faith (Jude 1:20).
Ultimately, however, by studying systematic theology, we will help fulfill the Great Commission (Matthew 28:19-20), which commands us to, “go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.”
The key, there, is the word “teaching.” How can we make disciples if we lack the wherewithal to teach them what the Word of God says? And therein lies the answer to the opening question of this article. We need systematic theology because we have the Bible, not to replace the Bible. They fit together like a hand in a glove.
Recent studies from Barna and American Bible Society reveal there is a surge in interest in the Bible among young people; however, the gap between their enthusiasm for reading the Bible and their ability to understand it is large. That gap seems to be in the area of discipleship; in short, the lack of a thorough working knowledge of the whole counsel of God (Acts 20:27, NKJV).
Far from being reserved for academics, seminary students, or pastors, systematic theology may be just what you’re looking for to help you (a) understand your faith better, and with more conviction, and (b) speak with more authority when asked questions about what you believe and why.
Systematic theology is familiar, fun, and fulfilling.
And there is no better way to study it than with the gold standard of systematic theology books: Wayne Grudem’s Systematic Theology: An Introduction to Biblical Doctrine, 2nd ed. Systematic Theology, along with the many helps offered by ChurchSource to make reading Grudem’s book even more beneficial to your faith, are listed below.
Or, when you visit the ChurchSource website, type “systematic theology” or “Wayne Grudem” into the search bar and you’ll discover a treasure trove of titles we’re confident you’ll enjoy.
References:
Wayne Grudem, Systematic Theology: An Introduction to Biblical Doctrine, 2nd ed. (Grand Rapids: ZondervanAcademic, 2020), 1. Grudem acknowledges his former teacher, John Frame, with coining that definition. Italics in the original. Grudem, xxi. Grudem, 6.
“How Millennials and Gen Z Are Driving a Bible Reading Comeback,” Barna Research Group, November 6, 2025. https://www.barna.com/trends/bible-reading-trends/, accessed February 17, 2026.
John Farquahar Plake, “The Bible in America Today,” American Bible Society (April 2025, 11-12): 11-12, https://www.americanbible.org/wp-content/uploads/2024/12/SOTB-2024-12-Final-1.pdf, accessed February 17, 2026.
Bill Murphy, MS Communication (Grand Valley State University), MA Apologetics (Luther Rice College & Seminary) loves reading broadly, researching deeply, listening to music of many types and genres, and writing about theology, music, movies, culture, and anything else that catches his interest. He lives in West Michigan with his wife, Beth, and his cat, Larry.