Summary of my most recent class in pursuit of my Master’s in Theology at Colorado Christian University.
Written by Steven Barto, B.S. Psy.
Reflecting primarily, but not exclusively, on Wayne Grudem’s definition of systematic theology and his four, attendant sub-points (pp. 21-26), identify the biggest, most important idea for you about systematic theology?
“Biggest” can happen due to several factors: an idea which produced an “a-ha” moment while reading about it; an idea which has evaded your understanding until this session; an idea which you believe to be the most important one from all the readings of this session; or an idea which produces in you a deep sense of worship or wonder or even conviction.
The following is my response to the above discussion prompt.
The “biggest” or most important idea about why I chose to undertake the systematic study of theology is “clarity.” If, during my introduction to theology, I were to focus on systematic theology versus the “doctrine” of the Word of God, I would get sucked in to the vortex of the different forms of God’s Word (to include spoken or revealed versus written—sometimes explained as special revelation). That argument is enough to fill an entire tome itself. It would, by its very nature, include hermeneutics (the branch of knowledge that deals with interpretation, especially of the Bible or literary texts). I’d have to address apocryphal versus canonical. Then I’d have to examine authority, clarity, sufficiency, and necessity. I’d need to consider which translation is most accurate and suited for exegetical study. It’s enough to make the beginner theology student exclaim, “What have I gotten myself into?”
I can, however, focus on what I consider that one biggest idea. My choice surrounds the vital factor of conviction. Certainly, it is important to examine Christian beliefs and disciplines in relation to other systems of thought or practice. There is an element of historical theology in this exercise. What are the insights, analyses, and conclusions that have been handed down, and are they germane to the subject being studied at this time? Obviously, it is critical that systematic theology aid us in applying Christian doctrine to present-day circumstances. We’re told Christ is the same, always. We’re informed that God’s Word will never pass away. Accordingly, at least some portion of what’s before us must apply to the current situation. Further, how would we arrive at any sensible understanding of historical and applicable theology if the study itself is disorganized? By default, it would therefore not be systematic.
There is only one solution. As Wayne Grudem notes, systematic theology must treat biblical topics “in a carefully organized way to guarantee that all important topics will receive thorough consideration.”  Systematic theology, among other functions, helps assure the universal inclusion of approved doctrine for study, for edification, and for church governance. And what is “doctrine?” Grudem calls what the whole Bible teaches us about a topic “doctrine.” Although somewhat circular in its explanation, doctrine is simply “the result of the process of doing systematic theology with regard to one particular topic.”  To make matters more complex, a doctrine can be very broad in scope or very narrow. God, in general, is a rather broad doctrine; however, the trinity is a specific topic relative to the Doctrine of God.
Every general doctrine in Christianity holds within it the potential to be dissected into intricately yet equally important sub-sections of doctrine. Not surprisingly, each section or sub-section can be the subject of any number of teachings, and to varying degrees of depth. This might sound discouraging at best, and frighteningly complex at worst. To take this stand would be to miss the point. “Systematic” simply means “done to a fixed plan or system.” In other words, methodical if not (at least to some degree) universal. Systematic theology must concern itself with the “core” doctrines that define and vitalize Christianity.
The biggest, most important aspect of systematic theology is the appropriate definition and inclusion of doctrinal categories. Grudem sees these as critical enough to state they must meet at least one of the following three criteria: 
- Doctrines most emphasized in Scripture;
- Doctrines most significant throughout the history of the Christian church and deemed important for all Christians at all times;
- Doctrines that have become important for Christians in the present situation in the history of the church.
Wayne Grudem provides a comprehensive listing of core Christian doctrines that I believe should be a part of any systematic theology:
- Part 1: The Doctrine of the Word of God
- Part 2: The Doctrine of God
- Part 3: The Doctrine of Man
- Part 4: The Doctrines of Christ and the Holy Spirit
- Part 5: The Doctrine of the Application of Redemption
- Part 6: The Doctrine of the Church
- Part 7: The Doctrine of the Future
Grudem’s list is not necessarily the “last word” regarding what is often included in a listing of Christian doctrine. It is, in my opinion, comprehensive to the extent that it is based upon sound biblical exegesis. Moreover, it is not unduly lengthy and cumbersome. For example, the Association of Certified Biblical Counselors expands the list of biblical doctrines as follows:”
- Grace (already covered under the doctrine of redemption)
- Sin (already covered under the doctrine of man)
- Regeneration (already covered under the doctrine of redemption)
- Justification (already covered under the doctrine of redemption)
- Sanctification (already covered under the doctrine of redemption)
- The Great Commission (although not a specific doctrine in Grudem’s Systematic Theology text book, it could be argued this belongs under the Doctrines of Christ and the Holy Spirit, sub-category “the offices of Christ”) 
While it can be argued that the above expanded version of the basic Doctrines of Christianity (at least as they are outlined by Grudem’s text book), it is Grudem himself who states, “In a broader sense, ‘all that Jesus commanded’ includes the interpretation and application of his life and teachings, because in the book of Acts it is implied that it contains a narrative of what Jesus continued to do and teach through the apostles after his resurrection.”  Further, Grudem argued that, in a larger sense, “all that Jesus commanded” includes everything contained in the New Testament.
Given the magnitude of parables, teachings, instructions, sermons, and sayings of Jesus, and in light of Grudem’s statement that all of the New Testament contains commandments from Christ, I believe the biggest, most important idea for systematic theology remains the accepted and limited (for lack of a better term) listing of doctrines provided by Grudem in Systematic Theology. These doctrines pass the test he applied to them on page 25 (and discussed above). Without a clearly acceptable and limited list of Christian doctrines, systematic theology loses its very critical function: to provide a unified, accepted list of doctrines to be followed throughout the community of believers.
 Wayne Grudem, Systematic Theology. (Grand Rapids: Zondervan, 24), 2000.
 Grudem, p. 25.
 Ibid, p. 25.
 Association of Certified Biblical Counselors, “Standards of Doctrine.” (Kansas City: Assn. Cert. Biblical Counselors, 2018).
 Grudem, p. 27.