Lesson 6 – [Homiletics] Systematic Theology

Systematic Theology

Proverbs 22:20-21: Have not I written to thee excellent things in counsels and knowledge,21 That I might make thee know the certainty of the words of truth; that thou mightest answer the words of truth to them that send unto thee?

As the apostle Paul delivered his valedictory speech to the Ephesian elders assembled on the shore-lines of Miletus (see Acts 20:17, 38), he was able to confidently affirm that there was nothing of consequence missing from the teaching he had provided to the people of God. “For,” says he, “I have not shunned to declare unto you all the counsel of God” (Acts 20:27). In modern terms, in regard to his teaching method, Paul was a committed systematic theologian, one who has a command of all scriptural, divine truths. Luke, the “beloved physician” of Paul (Colossians 4:14), wrote that he had “perfect understanding of all things from the very first” concerning his biographical knowledge of Christ (Luke 1:3-4). Such a sweeping knowledge is incumbent upon the would-be Christian minister, who is commissioned by his Lord to instruct the disciples in “all things whatsoever I have commanded you” (Matthew 28:20). Those who are “meet for the master’s use” are the vessels “prepared unto every good work” (II Timothy 2:21). As preachers, we must be a jack-of-all-trades, not an over-specialized madman.

A good preacher is one who, at the end of a period of much preaching to their congregation, may say with Paul, “thou hast fully known my doctrine” (II Timothy 3:10). There should not be important subjects or necessary teachings which their mature congregation is lacking in. Those who preach God’s word are “feeding” them (Acts 20:28; I Peter 5:2), and this analogy to food is helpful to see the need to be doctrinally systematic in our preaching schedule. For instance, though one can get a well-balanced, nutritious diet through a multitude of meal-plans, there are certain kinds of foods that any healthy diet will not be lacking in. We who teach the Bible should have the heart of that great evangelist, who wanted all persons to be brought to a “perfect,” or, complete, understanding of Christ and his word (Colossians 1:28; Ephesians 4:13). Of course, if a member of the church has a question or Biblical subject they would like to know more about, they should not be afraid to make suggestions to the teachers (Luke 11:1).

Principles of a Systematic Theology

  1. The Bible is a divinely-authoritative, united revelation.

Systematic theology draws its chief evidence and illustration from scripture (see I Corinthians 2:13; II Timothy 3:16-17), viewed as a composite and coherent whole. What is written by Moses in Deuteronomy, insofar as it is accurately interpreted, is part of the same strand of divine communication to man as, say, that which is written by Peter in I Peter. In principle, then, there could not only be no contradiction between Biblical truths, but actually appreciable overlap in ideas. When we want to discern the truth (in doctrine or in practice) about anything, we should comb the comprehensiveness of the canon, and draft our ideas with respect to the entirety of God’s word. As he prepares his teachings, a preacher should be concerned, first, foremost, and finally, with scripture, and, if he be systematic, he will not settle for a mere word from James, but will also want to see how this or that inspired song of David or this or that heavenly sermon of Jesus bears upon the present truth. Using extra-biblical material in our study and preaching is not wrong, of course (e.g., I Corinthians 9:7-8, 24; 11:14), but the surest and safest theology is one whose core is couched in the cleft of God’s word.

  1. Doctrine comes to us—and to our respective audience—gradually.

All doctrine comes piecemeal—“here a little, there a little” (see Isaiah 28:9-10). When God took Ezekiel through a tour of the abominations of Israel, he did so step by step (see Ezekiel 8), and when God led the children of Israel into the Promised Land, he did so city by city: “by little and little I will drive them out from before thee” (Exodus 23:30). There is a benefit but, more usually, also a danger in viewing a sermon as one’s last. Babies will not grow faster or better if you stuff their faces with five or six times what they can handle in a meal; will they not rather “vomit up” the morsel they have eaten, and “lose thy sweet words” (see Proverbs 23:8)? We ought to eat honey, “because it is good” (Proverbs 24:13), especially the “honey” of God’s word (Psalm 19:10), but too much at one time will induce a spiritual upheaval (see Proverbs 25:16). When we preach the Bible, we should content ourselves to the “here a little” ideology: don’t think that you have to cover every subject, nor even everything in a given subject, in one go. Lay one brick of truth a time, and soon you will find a strong tower; lay too many at once, and your building will be no building.

  1. Know what counts as evidence for a theological position, and what doesn’t.

True doctrine is one of the things the spiritual leader, of all believers, must “give attendance” and “take heed” to (I Timothy 4:13, 16), that they may take proper care of the church of God. When we swerve from interpretative caution, we will inevitably make logical and, oftentimes, doctrinal errors. The good systematic theologian will be hesitant to marshal for his support biased interpretations and half-baked expositions of scripture. They will not slay the primary sense of a text, for example, in their zeal to a doctrine (e.g., I John 5:7; Romans 10:4; 11:29), nor will they rest content with just one verse to buttress their belief. They can easily separate their rationality from their emotions and opinions as an impartial judge of right teaching, and they don’t settle for just-so explanations/theories. They critically receive and assess everything they hear (Proverbs 14:15; I Thessalonians 5:21), even if it already accords with their preconceived ideas. As a wise man, the diligent Bible-teacher “useth knowledge aright” (Proverbs 15:2), after having understood both the “proverb” (the passage) and the “interpretation” (the meaning) (see Proverbs 1:6).

Categorization of Doctrines

The doctrines of scripture can be categorized in different ways, depending on the purpose of the sorting.

  1. By Content

A systematic theology can be academically arranged and analyzed under doctrinal headings, which divide Biblical truths into respective theological areas of content. This can be practically helpful when we write sermons, because it allows us to narrow our thoughts upon a very specific area. Here are the classical systematic theology headers:

  • Theology Proper: the study of God (e.g., the trinity, the nature of God)
  • Christology: the study of Christ (e.g., the incarnation, the ministry of Christ)
  • Pneumatology: the study of the Holy Spirit (e.g., the gifts of the Spirit, the ministry of the Spirit)
  • Bibliology: the study of the Bible (e.g., revelation, preservation)
  • Anthropology: the study of man (e.g., the nature of man, the purpose of man)
  • Angelology: the study of angels (e.g., the nature of angels, the ministry of angels)
  • Soteriology: the study of salvation (e.g., justification by faith, election)
  • Ecclesiology: the study of the church (e.g., church government, church discipline)
  • Hamartiology: the study of sin (e.g., covetousness, pride)
  • Eschatology: the study of the end times (e.g., the antichrist, the new heavens and new earth)
  1. By Class

Another way to systematically categorize and analyze doctrines is by their rank. Here, we recognize that not all Biblical teachings are equal in their significance, and that some teachings are more necessary or more important for the believer. Given that there are stern warnings in scripture against “damnable heresies” (II Peter 2:1; see also II John 9), or, false teachings which affect one’s personal salvation, truly not all doctrines are made equal (see also Matthew 23:23). Traditionally, Christian thinkers have non-systematically sub-divided all doctrines into one of two categories: essential or non-essential. For example, Augustine is credited with having wrote that we ought to have “in essentials, unity; in non-essentials, liberty; in all things, charity.” While this is well and good, it really oversimplifies the complex network of Biblical truths. Below is a proposed five-tier doctrine-ranking system which helps us to categorize, by class, any Biblical teaching. Understanding this, at least in principle if not fully in practice, assists a preacher on what to devote more time to in their teaching, and what to be more loose/free on as opposed to what to be tighter/intolerant of dissent on.

One can conceptually divide doctrines into these five categories (e.g., the doctrine of salvation by faith alone in Tier I, the doctrine of Biblical inspiration in Tier II, the doctrine of the rapture in Tier III, etc.), and/or they can tease out aspects of a doctrine across the spectrum (e.g., the doctrine of creation in Tier II, the doctrine of Adam as a figure of Christ in Tier III, the doctrine of the narrative events of the fall of man in Tier IV, and the doctrine of what fruit it was that Adam ate in Tier V). The decision on ranking a doctrine is not arbitrary. For instance, Tiers I, II, and III are divided from Tiers IV and V on the rule that, to be essential/fundamental/significant, a doctrine must have at least one passage with a primary interpretation teaching that truth. Again, Tiers I and II differ in their extremeness: one must believe Tier I doctrine to be saved, but one must be merely receptive to believing Tier II doctrine to be saved. And again, though we might wonder why Ahasuerus had the book of records read to him when he could not sleep (see Esther 6:1), or what the wrong may have been which Onesimus did against Philemon (Philemon 11, 18), or exactly how many crowns a faithful disciple will receive in heaven, these thoughts, though they be grounded in the Bible, are mere conjecture, and do not significantly affect the main message or teaching of scripture, and are thus Tier V.

  1. By Complexity

Yet another manner we have of categorizing our doctrine systematically is to evaluate its complexity or simplicity. Paul speaks of “the deep things of God” (I Corinthians 2:10), the “wisdom” he taught “among them that are perfect” (I Corinthians 2:6). Peter says of some of Paul’s writings that they are “hard to be understood” (II Peter 3:16), implying that doctrines can be organized into their gradating difficulty level. This is a throughgoing Biblical distinction, too. Paul and the author of Hebrews differentiate between the doctrinal “milk” (easy, simple) and “meat” (hard, complex) (see I Corinthians 3:1-2; Hebrews 5:12-14). The latter, after utilizing this idea in rebuke to his audience, proceeds to briefly sketch out a few areas of theology in his listing of what he terms “the principles of the doctrine of Christ” (Hebrews 6:1-2), or, the doctrine in/from Christ; as we might say today, “the basic principles of Christian doctrine.” Because he lists areas of theology as diverse one from another as, say, soteriology (“of faith toward God”) and eschatology (“of resurrection of the dead”), we may observe that certain teachings are by their nature complex, but that every teaching of scripture has aspects which are hard and easy about it.

There doesn’t seem to be any good reason to quantify the difficulty-level of doctrines beyond this, however. All Biblical teachings probably lie on a complexity spectrum, with no discreet breaks, or hard and fast rules of division between, say, very easy and easy, or between easy and intermediate. It is enough that we take note, merely, of whether it is a more bottom-shelf doctrine, or if it is headier, that we may obey the injunction to “mind not high things, but condescend to men of low estate” (Romans 12:16), and so that the “common people” will hear us gladly (see Mark 12:47). When we accurately identify a doctrine as more complex, we will give it more time in its exposition, and more care in its application. There are far too many preachers who, for instance, quoting and explaining Ephesians 2:8-9 or John 3:16 for a protracted time period for the fifteenth time in a month, have not even the beginning of wisdom on this count.

How to Deal with Doctrinal Disagreements

According to Paul, false teaching is a work of the flesh (Galatians 5:20), and, if we were properly and fully yielded to the Holy Ghost’s influence in our life, it would be largely—if not entirely—avoided (“he will guide you into all truth,” John 16:13; his anointing upon us “is truth, and is no lie,” I John 2:27). However, how should believers deal with disagreements they may have with one another? Here is an acronym that will help you to ACT properly in such situations:

  1. Assess the doctrine. When a fellow believer advocates for a teaching which we disagree with, we must be careful to first assess what the disagreement is, both by understanding what they are actually saying and what we ourselves ought to think about the matter. Think before you speak (see Proverbs 29:20; James 1:19), “lest he that heareth it put thee to shame, and thine infamy turn not away” (Proverbs 25:10). It could be that the “certain strange things” which are brought to your ears are indeed true (see Acts 17:20). Don’t feel like you always have to say what’s on your mind (see Proverbs 29:11).
  2. Contend for the truth. If you find that the doctrinal disagreement is significant enough to warrant your involvement, and that you have the right position, you should cordially begin to contend for the truth. It is best to “reason out of the scripture” (Acts 17:2) with the other believer(s), to attempt to convince them by appealing to God’s word. Depending on the doctrine, it may be more helpful to be defensive in your approach, not necessarily always offensive. Make them prove their case—don’t let them get away with weak arguments or paltry evidence. Don’t be the fool who has to resort to fallacious reasoning (straw-man attacks, red-herrings, non-sequiturs, false analogies, etc.) to make his case. Be logical, and be persuasive: “how forcible are right words! But what doth your arguing reprove?” (Job 6:25). If the person has won you over, don’t go on in your folly, but repent post-haste, and thank them for teaching you.
  3. Terminate the disagreement. Try not to leave doctrinal questions indefinitely inconclusive. Be a studious Christian, who always applies their heart “to know, and to search, and to seek out wisdom, and the reason of things” (Ecclesiastes 7:25). Attempt to get wiser with time through these Biblical skirmishes, using them to develop your own grasp of doctrine. Don’t be a fake “peace-keeping” Christian who doesn’t care for the truth, but instead for uninterrupted “unity.” Be passionate about doctrinal differences, especially if they are significant (see Acts 15). If the other person(s) could not be convinced, and you are confident in your own position, determine in your heart to chew the cud of that contention for a while, and try to, sooner or later, bring the case to a close, if not with them, then certainly with yourself.