All Scripture, whether examined exegetically in particular texts or categorically within the full scope of the Bible, is spiritually profitable to accomplish at least four divine purposes (2 Tim. 3:16):
1. For establishing “teaching” or doctrine, that is, God’s inspired self-disclosure about himself, his created world, and his redemptive plan to save and sanctify sinners
2. For confrontation or “reproof” of sin, whether in the form of false teaching or disobedient living
3. For “correction” of error in thinking and behaving so that the repentant one can be restored to the place of pleasing God
4. For “instruction” so that believers can be habitually trained to practice the righteousness of the Lord Jesus Christ—sinning less and obeying more
Scripture provides the only complete, wholly accurate, and trustworthy teaching about God, and it will sufficiently accomplish these four things for equipping “the man of God” (2 Tim. 3:17).
Systematic theology can provide several benefits:
1. An unabridged collection of biblical truth
2. An orderly synthesis and summation of biblical doctrine
3. An imperative to take the gospel to the ends of the earth
4. A repository of truth for expositional preaching and teaching
5. A scriptural basis for Christian behavior in the church, the home, and the world
6. A defense of biblical doctrine against false teaching
7. A biblical response to ethical and social malpractice in the world
As James Leo Garrett Jr. puts it,
Systematic theology is beneficial as an extension of the teaching function of the churches, for the orderly and integrated formulation of biblical truths, for the undergirding of the preaching of preachers and lay Christians, for the defense of gospel truth against error that has invaded the church, for the legitimation of the gospel before philosophy and culture, as the foundation for Christian personal and social ethics, and for more effective universal propagation of the gospel and interaction with adherents of non-Christian religions.
Systematic theology can be limited by the following factors:
1. The silence of the Bible on a particular topic (Deut. 29:29; John 20:30; 21:25)
2. A theologian’s partial knowledge/understanding of the entire Bible (Luke 24:25–27, 32; 2 Pet. 3:16)
3. The inadequacy of human language (1 Cor. 2:13–14; 2 Cor. 12:4)
4. The finiteness of the human mind (Job 11:7–12; 38:1–39:30; Rom. 11:33–35)
5. The lack of spiritual discernment/growth (1 Cor. 3:1–3; Heb. 5:11–13)
What Is the Relationship of Systematic Theology to Doctrine?
Doctrine represents teaching that is considered authoritative. When Christ taught, the crowds were amazed at his authority (Matt. 7:28–29; Mark 1:22, 27; Luke 4:32). A church’s “doctrinal” statement contains a body of teaching used as the standard of authoritative orthodoxy.
In the Old Testament, the Hebrew word laqakh means “what is received” or “accepted teaching” (Deut. 32:2; Job 11:4; Prov. 4:2; Isa. 29:24). It can be variously translated as “instruction,” “learning,” or “teaching.”
In the New Testament, two Greek words are translated as “doctrine,” “instruction,” or “teaching”: didachē (referring to the content of teaching) and didaskalia (referring to the activity of teaching). Paul used both words together in 2 Timothy 4:2–3 and Titus 1:9.
In Latin, doceo, “to teach,” doctrina, “what is being taught,” and doctor, “the one who is teaching,” all contribute to the meaning of the English word doctrine. The content may be informational (to be believed) or practical (to be lived out). It does not necessarily refer to categorized truth.
Biblically speaking, the word doctrine is a rather amorphous term that only takes shape in context. It refers to general teaching (systematized or not, true or false), such as the “teaching of Balaam” (Rev. 2:14) or “human teachings” (Col. 2:22), in contrast to biblical teaching such as Christ’s teaching (Matt. 7:28) or Paul’s teaching (2 Tim. 3:10).
Biblical doctrine, therefore, refers to the teaching of Scripture, whether it be proclamational, expositional, or categorical. That makes all Scripture “doctrinal,” whether it be read, taught, preached, or systematized into theological categories. Systematic biblical doctrine (systematic theology) refers to a categorical summation of biblical teaching that follows normally employed themes or categories.
A survey of Scripture shows that all doctrine or teaching can generally be classified into one of two categories depending on its source:
• with regard to origin—from God the Creator (John 7:16; Acts 13:12) or from God’s creation (Col. 2:22; 1 Tim. 4:1)
• with regard to truth content (2 Thess. 2:11–12)—true or false
• with regard to human source (1 Thess. 2:13)—biblical or unbiblical
• with regard to quality (1 Tim. 1:10; 6:3)—sound or unsound
• with regard to acceptability (1 Tim. 1:3; Heb. 13:9)—familiar or strange
• with regard to retention (Rev. 2:24)—to hold or not to hold
• with regard to benefit (1 Tim. 4:6)—good or bad
• with regard to value (2 Tim. 3:16)—profitable or unprofitable
The modern theological use of the term doctrine is too narrow, distorts the primary biblical use of the term, and can be misleading. It is far better in discussing doctrine to use the term in its broader sense of “teaching” (which certainly includes systematized truth but is not limited to this use) rather than to use doctrine in its secondary sense as though this were the only sense. The teaching of Scripture serves as the yardstick, gauge, standard, paradigm, pattern, measure, and plumb line by which all other teaching on any given subject is determined to be true or false, received or rejected, sound or unsound, orthodox or heretical.
Sound biblical doctrine has many implications for the life of Christ’s church:
1. Sound doctrine exposes and confronts sin and false doctrine (1 Tim. 1:8–11, esp. 1:10; 4:1–6).
2. Sound doctrine marks a good servant of Christ Jesus (1 Tim. 4:6; see also 1 Tim. 4:13, 16; Titus 2:1).
3. Sound doctrine is rewarded with double honor for elders (1 Tim. 5:17).
4. Sound doctrine conforms to godliness (1 Tim. 6:3; Titus 2:10).
5. Sound doctrine is included in the apostolic example to follow (2 Tim. 3:10).
6. Sound doctrine is essential to equipping pastors (2 Tim. 3:16–17).
7. Sound doctrine is the continual mandate for preachers (2 Tim. 4:2–4).
8. Sound doctrine is a basic qualification for eldership (Titus 1:9).
Scripture teaches that there will always be opposition to sound doctrine, both by humans (Matt. 15:2–6; Mark 11:18; 1 Tim. 1:3, 10; 2 Tim. 4:3; Titus 1:9) and by Satan and demons (1 Tim. 4:1). The Bible outlines several antidotes/corrections to false doctrine:
1. Speaking the truth of sound doctrine in love (Eph. 4:15)
2. Teaching sound doctrine (1 Tim. 4:6; 2 Tim. 4:2)
3. Holding fast to sound doctrine (Titus 1:9; Rev. 2:24–25)
4. Refuting false doctrine (Titus 1:9)
5. Rejecting and turning away from teachers of false doctrine (Rom. 16:17; 2 John 9–10)
There is a direct, inseparable relationship between sound doctrine and saintly living, something Scripture teaches clearly and consistently (Rom. 15:4; 1 Tim. 4:16; 6:1, 3; 2 Tim. 3:10; Titus 2:1–4, 7–10). The reverse is also true—where there is false belief, there will be sinful behavior (Titus 1:16). In spite of Scripture’s clear emphasis on both purity of doctrine and purity of life, a number of mistaken notions have arisen concerning the relationship between what a person believes and how a person should live. These wrong ideas include the following:
1. Right doctrine automatically leads to godliness.
2. It doesn’t matter how a person lives so long as he or she has right doctrine.
3. Doctrine deadens, spiritually speaking.
4. There is no connection between what one believes and how one lives.
5. Christianity is life, not doctrine.
6. Doctrine is irrelevant.
7. Doctrine divides.
8. Doctrine drives people away.
In contrast to the negativity aimed at doctrine, the absence of sound doctrine and the presence of false doctrine will always lead to sinful behavior. Without sound doctrine, there is no scriptural basis to delineate right from wrong, no doctrinal authority to correct sin, and no biblical encouragement to motivate godly living.
On the other hand, the spiritual value of sound doctrine is incalculable:
1. Sound doctrine is spiritually profitable (2 Tim. 3:16–17).
2. Spiritual blessings are promised for obedience (Rev. 1:3; 22:7).
3. Sound doctrine guards against sin (e.g., Job, Joseph, Daniel, Christ).
4. Sound doctrine delineates between truth and error (2 Cor. 11:1–15; 2 Tim. 3:16–17).
5. Sound doctrine was central to Christ’s ministry (Matt. 7:28–29; Mark 4:2; Luke 4:32).
6. Sound doctrine was central in the early church (Acts 2:42; 5:28; 13:12).
7. Sound doctrine was central to apostolic ministry (Paul: Acts 13:12; 17:19; Gal. 2:11–21; John: 2 John 9–10).
8. Martyrs gave their lives for sound doctrine (Christ: Mark 11:18; Stephen: Acts 7:54–60; James: Acts 12:2; Paul: 2 Tim. 4:1–8).
9. Christ and the apostles left a mandate to pass sound doctrine on to the next generation (Christ: Matt. 28:20; Paul: 2 Tim. 2:2).
10. Churches were commended for sound doctrine or condemned for lack of sound doctrine (Ephesus, commended: Rev. 2:2, 6; Pergamum and Thyatira, condemned: Rev. 2:14–15, 20).
11. Established sound doctrine anticipates and prepares for eras when sound doctrine is out of season (2 Tim. 4:3).
12. Sound doctrine protects the church from false teachers (Titus 1:9).
13. Sound doctrine provides true spiritual adornment for believers (Titus 2:10).
14. Sound biblical teaching and sound systematic doctrine are inseparably connected to “theology.” Whether it be expositionally viewed in a text of Scripture or comprehensively categorized from all Scripture, biblical teaching cannot be disconnected from its identification with theology. Put another way, all biblical teaching is theological in nature, and all Christian theology is biblical in content.
What Is the Overarching and Unifying Theme of Scripture?
The broad theme of king/kingdom (human and divine) appears throughout the Bible. With the exceptions of Leviticus, Ruth, and Joel, the Old Testament explicitly mentions this theme in thirty-six of its thirty-nine books. Except for Philippians, Titus, Philemon, and 1, 2, and 3 John, the New Testament directly mentions the subject in twenty-one of its twenty-seven books. All in all, fifty-seven of the sixty-six canonical books include the kingdom theme (86 percent).
The Hebrew words for “king,” “kingdom,” “reign,” and “throne” appear over three thousand times in the Old Testament, while the Greek words for these terms appear 160 times in the New Testament. The first Old Testament mention occurs in Genesis 10:10 and the last in Malachi 1:14. The initial appearance in the New Testament comes in Matthew 1:6 and the last in Revelation 22:5.
The exact expression “kingdom of God” does not appear in the Old Testament. In the New Testament, Matthew alone uses the phrase “kingdom of heaven,” but he uses it interchangeably with “kingdom of God” (Matt. 19:23–24). And where he uses “kingdom of heaven” in passages that parallel other Gospels, those Gospel writers use “kingdom of God” (cf. Matt. 13:11 with Luke 8:10), thus establishing the correspondence between these two phrases.
Jesus never precisely defined “kingdom of heaven/God” in the Gospels, although he often illustrated it (e.g., Matt. 13:19, 24, 44, 45, 47, 52). Surprisingly, no one ever asked Christ for a definition. It can be assumed that they at least thought they understood the basic idea from the Old Testament, even if their ideas were mistaken.
Most telling, perhaps, is the plethora of King titles given to Christ in the New Testament:
• “King of Israel” (John 1:49; 12:13)
• “King of the Jews” (John 18:39; 19:3, 19, 21)
• “King of kings” (1 Tim. 6:15; Rev. 17:14; 19:16)
• “King of the ages, immortal, invisible” (1 Tim. 1:17)
• “King of the nations” (Rev. 15:3)
His reign is said to be forever and ever (Rev. 11:15; 22:5).
A biblical study of God’s kingdom would lead one to conclude that it is multifaceted, multidimensional, multifocal, multifactorial, and multifarious. It certainly could not be considered monolithic in character.
The idea of God’s kingdom encompasses every stage of biblical revelation. For instance,
• God is King of eternity (pre-Genesis 1, Revelation 21–22, post-Revelation 22)
• God is King of creation (Genesis 1–2)
• God is King of history (Genesis 1–Revelation 20)
• God is King of redemption (Genesis 3–Revelation 20)
• God is King of the earth (Genesis 1–Revelation 20)
• God is King of heaven (pre-Genesis 1, Genesis 1–Revelation 22, post-Revelation 22)
All kingdom of God passages can be summarized by recognizing several broad aspects. First is the universal kingdom, which includes the rule of God that has been, is, and forever will be over all that exists in time and space. Second is God’s mediatorial kingdom, in which he rules on earth through divinely chosen human representatives. Third is the spiritual or redemptive aspect of God’s kingdom, which uniquely deals with a person’s salvation and personal relationship with God through Christ. When Scripture uses the word “kingdom” to refer to God’s kingdom, it could point to any one aspect of the kingdom or several of its parts together. Careful interpretation in context will determine the particulars for a given biblical text.
With these ideas in mind, it is proposed that God as King and the kingdom of God should together be seriously considered as the grand, overarching theme of Scripture. A number of noble ideas have been considered in the past, such as the glory of God, redemption, grace, Christ, covenant, and promise. Each possibility explains a part of God’s kingdom, but only God’s kingdom explains the whole.
From before the beginning until after the end, from the beginning to the end, both in and beyond time and space, God appears as the ultimate King. God is central to and the core of all things eternal and temporal. The kingdom of God convincingly qualifies as the unifying theme of Scripture.
John Bright succinctly and eloquently captured this thinking as follows:
Old Testament and New Testament thus stand together as the two acts of a single drama. Act I points to its conclusion in Act II, and without it the play is an incomplete, unsatisfying thing. But Act II must be read in the light of Act I, else its meaning will be missed. For the play is organically one. The Bible is one book. Had we to give that book a title, we might with justice call it “The Book of the Coming Kingdom of God.” That is, indeed, its central theme everywhere.
The authors of this volume would only edit Dr. Bright’s brilliant summary by deleting one word, “Coming.” For God’s kingdom has been, is, and forevermore shall be.
The kingdom of God can be explained in this manner: The eternal triune God created a kingdom and two kingdom citizens (Adam and Eve) who were to have dominion over it. But an enemy deceived them, seduced them into breaking allegiance to the King, and caused them to rebel against their sovereign Creator. God intervened with consequential curses that exist to this day. Ever since, he has been redeeming sinful, rebellious people to be restored as qualified kingdom citizens, both now in a spiritual sense and later in a kingdom-on-earth sense. Finally, the enemy will be vanquished forever, as will sin. Thus, Revelation 21–22 describes the final and eternal expression of the kingdom of God, where the triune God will restore the kingdom to its original purity with the curse having been removed and the new heaven and the new earth becoming the everlasting abode of God and his people.
 MacArthur, J., & Mayhue, R., eds. (2017). Biblical Doctrine: A Systematic Summary of Bible Truth (pp. 39–44). Crossway.