Themes & Doctrine
Systematic theology organizes Scripture's teachings into branches. Each branch is a complete discipline — with its own questions, key texts, and the Church's historical debates.
How to use
Each section presents the theological branch, the fundamental questions it addresses, the main positions, and the decisive Scripture texts.
🏛️ Bibliology — The Doctrine of Scripture
Central question: What is the Bible and how does it function as authority?
Bibliology studies the nature, origin, authority, and sufficiency of Scripture.
Inspiration
The Bible is not merely human wisdom about God — it is God's word in human words.
- Verbal plenary inspiration: Every word of the original Scripture is God-breathed (2 Tim 3:16 — theopneustos = "breathed out by God")
- Organic inspiration: God used the personalities, styles, and contexts of the human authors — not mechanical dictation
- Key text: "No prophecy of Scripture comes from someone's own interpretation… men spoke from God as they were carried along by the Holy Spirit" (2 Pet 1:20–21)
Authority and Inerrancy
- Inerrancy: The original Scripture is without error in all it affirms — including history and science (rightly interpreted)
- Infallibility: Scripture does not mislead in its purpose — salvation and godly living
- Canon: 39 OT + 27 NT books = 66 books recognized as authoritative by the Church
- Apocrypha: Deuterocanonical in Catholic/Orthodox tradition; non-canonical in Protestantism
Clarity and Sufficiency
- Perspicuity: Scripture's saving message is sufficiently clear for any open-minded reader
- Sufficiency: Scripture provides everything needed for salvation and godly life — nothing must be added (2 Tim 3:16–17)
| Principle | Definition | Key Text |
|---|---|---|
| Sola Scriptura | Scripture alone = supreme authority | Isa 8:20; 2 Tim 3:16 |
| Analogia fidei | Scripture interprets Scripture | 1 Cor 2:13 |
| Sensus plenior | Deeper meaning intended by God | Matt 2:15 ← Hos 11:1 |
| Hermeneutics | The science of correctly interpreting the text | Neh 8:8 |
🔱 Theology Proper — The Doctrine of God
Central question: Who is God and what is He like?
The Existence of God
- Cosmological argument: Every effect has a cause; the universe requires an uncaused Cause (Rom 1:20)
- Ontological argument: The greatest conceivable being must exist in reality
- Teleological argument: The complex design of creation points to a Designer (Ps 19:1)
- Moral argument: The universal moral law implies a moral Lawgiver (Rom 2:14–15)
The Attributes of God
Incommunicable attributes (unique to God):
| Attribute | Definition | Key Text |
|---|---|---|
| Aseity | Self-existence — depends on nothing outside Himself | Exod 3:14; John 5:26 |
| Immutability | Does not change in being, character, or purpose | Mal 3:6; Jas 1:17 |
| Eternity | Without beginning or end; beyond time | Ps 90:2; John 8:58 |
| Omnipresence | Everywhere present simultaneously | Ps 139:7–10; Jer 23:24 |
| Omniscience | Knows all — past, present, future, possible | Ps 147:5; 1 John 3:20 |
| Omnipotence | Can do anything consistent with His nature | Gen 18:14; Matt 19:26 |
| Sovereignty | Absolute governance over all things | Dan 4:35; Rom 11:36 |
| Simplicity | Not composed of parts — cannot be divided | Deut 6:4; John 4:24 |
Communicable attributes (partially reflected in humanity):
| Attribute | Key Text |
|---|---|
| Holiness | Isa 6:3; Rev 4:8 |
| Love | 1 John 4:8; John 3:16 |
| Justice / Righteousness | Ps 89:14; Rom 3:25–26 |
| Mercy / Compassion | Exod 34:6–7; Eph 2:4–5 |
| Truth | John 14:6; Heb 6:18 |
| Goodness | Ps 107:1; Matt 19:17 |
| Wisdom | Prov 3:19; Rom 11:33 |
| Jealousy (for good) | Exod 20:5; 2 Cor 11:2 |
The Trinity
God is one God existing in three persons — Father, Son, and Holy Spirit. Each person is fully God; there are not three gods.
- Unity: "Hear, O Israel: the LORD our God, the LORD is one" (Deut 6:4)
- Plurality: "Let us make man in our image" (Gen 1:26); baptism — Matt 3:16–17; Great Commission — Matt 28:19
- Modalist heresy (Sabellianism): Father, Son, Spirit are three modes of the same God — rejected
- Arian heresy: The Son is created, inferior to the Father — rejected at Nicaea AD 325
- Nicene formula: "True God from true God, begotten not made, of the same substance as the Father"
✝️ Christology — The Doctrine of Christ
Central question: Who is Jesus Christ?
Christology is the central branch of Christian theology — all others depend on the identity of Christ.
The Pre-existence and Divinity of Christ
- "In the beginning was the Word… and the Word was God" (John 1:1)
- "Before Abraham was, I am" (John 8:58 — direct use of God's name from Exod 3:14)
- "He is the image of the invisible God" (Col 1:15)
- "In him the whole fullness of deity dwells bodily" (Col 2:9)
- The 7 "I AM" declarations in John (6:35; 8:12; 10:9; 10:11; 11:25; 14:6; 15:1)
The Incarnation
"The Word became flesh and dwelt among us" (John 1:14) — God entered history as a human being.
- Virgin birth: Matt 1:18–25; Luke 1:26–38 — no human father, conceived by the Holy Spirit
- Purpose: Full identification with humanity (Heb 2:17), making atoning death possible, inaugurating the New Adam
- Kenosis (Phil 2:7): Christ "emptied himself" — not of divinity, but of glory and privilege; adopting human limitations
- Sinlessness: "He knew no sin" (2 Cor 5:21); "Tempted in every way as we are, yet without sin" (Heb 4:15)
The Two Natures
Defined at the Council of Chalcedon (AD 451): Christ is fully God and fully human — two natures in one person, without mixture, change, division, or separation.
| Heresy | Error | Rejected at |
|---|---|---|
| Docetism | Christ only appeared to be human | 1st–2nd century |
| Arianism | Christ is created, not eternally God | Nicaea 325 |
| Apollinarianism | Christ had no human mind | Constantinople 381 |
| Nestorianism | Two separate persons in Christ | Ephesus 431 |
| Eutychianism | The two natures were merged | Chalcedon 451 |
The Work of Christ — The Three Offices
Prophet: Reveals God and His will (Deut 18:15; John 1:18; Heb 1:1–2)
Priest: Mediates between God and man; makes atoning sacrifice (Heb 7–10; 1 Tim 2:5)
- The Great High Priest who is both the priest and the sacrifice
- Continues intercession in heaven (Rom 8:34; Heb 7:25)
King: Rules with sovereign authority (Luke 1:32–33; Eph 1:20–23; Rev 19:16)
- Kingdom inaugurated at first coming, consummated at second coming
Resurrection and Ascension
- Resurrection: Bodily, historical — empty tomb confirmed by enemies; 12+ appearances; 500+ witnesses (1 Cor 15:3–8)
- Ascension: To the Father's right hand — position of authority and intercession (Acts 1:9–11; Heb 1:3)
- Return: Will come back personally, visibly, in glory (Acts 1:11; Rev 19:11–16)
🌬️ Pneumatology — The Doctrine of the Holy Spirit
Central question: Who is the Holy Spirit and what does He do?
The Personality and Divinity of the Holy Spirit
The Holy Spirit is not a force or energy — He is a divine Person:
- Personality: Thinks (1 Cor 2:10–11), wills (1 Cor 12:11), feels (Eph 4:30), can be lied to (Acts 5:3–4)
- Divinity: Equal with Father and Son (Matt 28:19; 2 Cor 13:14); omniscient (1 Cor 2:10–11); omnipresent (Ps 139:7)
- Procession: The Spirit "proceeds from the Father" (John 15:26); Filioque ("and the Son") — East vs. West debate
The Works of the Holy Spirit
| Work | Definition | Key Text |
|---|---|---|
| Regeneration | New birth — new spiritual life given | John 3:5–8; Titus 3:5 |
| Indwelling | Permanent residence in believers | Rom 8:9–11; 1 Cor 6:19 |
| Sealing | Guarantee of salvation and God's ownership | Eph 1:13–14; 2 Cor 1:22 |
| Sanctification | Progressive transformation into Christ's likeness | Gal 5:22–23; 2 Cor 3:18 |
| Gifting | Spiritual gifts for edifying the Church | 1 Cor 12; Rom 12; Eph 4 |
| Filling | Ongoing control and empowering | Eph 5:18; Acts 4:31 |
| Conviction | Conviction of sin, righteousness, and judgment | John 16:8–11 |
| Intercession | Intercession with groanings too deep for words | Rom 8:26–27 |
Spiritual Gifts — The Continuationist Debate
Continuationism (Pentecostal, charismatic): All gifts — including tongues, prophecy, healing — continue today.
Cessationism (Reformed, Dispensationalist): Sign gifts (tongues, prophecy, miraculous healing) ceased with the completion of the canon and the death of the apostles.
Debated texts: 1 Cor 13:8–10; Eph 2:20; Heb 2:3–4
👤 Theological Anthropology — The Doctrine of Man
Central question: Who is man and what is his condition before God?
The Image of God (Imago Dei)
"Let us make man in our image, after our likeness" (Gen 1:26–27)
- Structural image: Capacities that distinguish man from animals — reason, moral will, creativity, language
- Functional image: Man as God's viceregent over creation — responsible dominion
- Relational image: Man created for relationship with God — vertical and horizontal
- Defaced image: Fallen through sin, but not destroyed (Gen 9:6; Jas 3:9)
- Restored image: In the process of restoration in Christ (Col 3:10; Eph 4:24)
The Structure of Human Nature
Dichotomy: Man = body + soul/spirit (considered the same thing) Trichotomy: Man = body + soul + spirit (three distinct elements — 1 Thess 5:23; Heb 4:12)
Regardless of position, Scripture affirms:
- Psychophysical unity: Man is not a soul trapped in an evil body — the body is good and destined for resurrection
- Intrinsic dignity: Every person bears the imago Dei — the foundation of Christian ethics (human rights, anti-slavery, pro-life)
⚡ Hamartiology — The Doctrine of Sin
Central question: What is sin and how does it affect us?
The Nature of Sin
Greek hamartia = "missing the mark" — but this understates the reality. Sin in Scripture includes:
| Term | Meaning | Text |
|---|---|---|
| Hamartia | Missing God's standard | Rom 3:23 |
| Parabasis | Transgression — deliberate violation of a law | Rom 5:14 |
| Anomia | Lawlessness — rejection of all divine law | 1 John 3:4 |
| Adikia | Unrighteousness — violation of God's justice | 1 John 5:17 |
| Poneria | Active wickedness — intentional moral corruption | Luke 11:39 |
Original Sin and the Fall
The theological framework:
- Original state: Adam and Eve created good (posse non peccare — capable of not sinning)
- The Fall (Gen 3): Free disobedience → corrupted nature → death
- Transmission: All humans inherit both Adam's guilt and his corrupted nature
Main positions:
- Augustinian realism: We all sinned in Adam in a real sense (Augustine, Reformed theology)
- Federal headship: Adam acted as humanity's representative; his guilt is imputed to us (Reformed)
- Pelagianism (heresy): Humans are born innocent; sin through imitation — rejected at Carthage AD 418
Total Depravity
Not that every person is as bad as possible, but that every aspect of human nature is corrupted:
- Mind (Rom 1:21; Eph 4:17–18), will (John 8:34; Rom 6:17), affections (John 3:19), conscience (1 Tim 4:2)
- Inability to come to God on one's own initiative (John 6:44; 1 Cor 2:14)
🙏 Soteriology — The Doctrine of Salvation
Central question: How is man saved?
The Order of Salvation (Ordo Salutis)
| Step | Definition | Key Text |
|---|---|---|
| Election (Predestination) | God chooses those who will be saved before the foundation of the world | Eph 1:4–5; Rom 8:29–30 |
| External calling | The proclamation of the gospel to all people | Matt 28:19; Rom 10:14 |
| Effectual calling | God irresistibly draws the elect | John 6:44; Rom 8:30 |
| Regeneration | New birth — new life given by the Spirit | John 3:3–8; Eph 2:1–5 |
| Faith and Repentance | Man's response to God's work | Acts 20:21; Eph 2:8–9 |
| Justification | Legal declaration of righteousness — forgiveness + imputation | Rom 3:21–26; Gal 2:16 |
| Adoption | The status of son/daughter of God | Gal 4:4–7; John 1:12 |
| Sanctification | Progressive transformation into Christ's likeness | 1 Thess 4:3; Phil 2:12–13 |
| Perseverance | True believers do not finally fall away | John 10:27–29; Phil 1:6 |
| Glorification | Complete glorification at the resurrection of the body | Rom 8:30; 1 John 3:2 |
The Calvinism–Arminianism Debate
Calvinism (TULIP):
- Total depravity — man unable to come to God
- Unconditional election — not based on foreseen faith
- Limited atonement — Christ intentionally died for the elect
- Irresistible grace — effectual calling cannot be refused
- Perseverance of the saints — the elect cannot be finally lost
Arminianism:
- Election based on foreknowledge of faith
- Christ died for all people
- Grace can be resisted
- Believers can fall finally from grace
Justification (Justificatio)
The most important theological distinction: Justification is forensic (legal) — a declaration from outside, not an internal transformation.
- What it is not: Infused righteousness (Rome sees justification + sanctification as an ongoing process)
- What it is: Full forgiveness of sins + imputation of Christ's righteousness (Rom 4:5; 2 Cor 5:21)
- Through faith alone (sola fide) — faith is the instrument, not our merit
- Saving faith produces works (Jas 2:14–26 — not a contradiction with Paul, but complementary)
⛪ Ecclesiology — The Doctrine of the Church
Central question: What is the Church and how does it function?
The Nature of the Church
- Ekklesia: The assembly of those called out (Gr. ekklesia = assembly)
- Universal Church: The totality of all believers across all times (Matt 16:18; Eph 1:22–23)
- Local Church: The concrete assembly of believers in a place (1 Cor 1:2; Rev 2–3)
The Marks of the True Church (Protestant Reformation)
- Pure preaching of the Word (notae ecclesiae)
- Correct administration of the sacraments/ordinances
- Church discipline (added by some Reformers)
Church Governance
| Model | Description | Denominations |
|---|---|---|
| Episcopal | Authority in hierarchical bishops | Catholicism, Orthodoxy, Anglicanism |
| Presbyterian | Rule by elected eldership | Presbyterianism, Reformed |
| Congregationalist | Autonomy of the local congregation | Baptist, Congregationalism |
Sacraments / Ordinances
Catholicism: 7 sacraments (grace conferred through performance — ex opere operato) Protestantism: 2 ordinances — Baptism and the Lord's Supper (signs and seals of grace)
Baptism:
- Paedobaptism (infant baptism): Covenant sign, corresponding to circumcision (Reformed, Lutheran, Anglican)
- Credobaptism (believer's baptism): Only for those who confess faith (Baptist, Anabaptist)
- Mode: Sprinkling (aspersion) vs. total immersion
The Lord's Supper:
- Transubstantiation (Catholic): Bread and wine become Christ's body and blood
- Consubstantiation (Lutheran): Christ present in, with, and under the bread and wine
- Spiritual presence (Calvin): Christ truly, spiritually present — but not bodily
- Memorialism (Zwingli/Baptist): Bread and wine are commemorative symbols
🔭 Eschatology — The Doctrine of Last Things
Central question: How will history end and what comes next?
Death and the Intermediate State
- Physical death: Separation of soul from body (Gen 3:19; Eccl 12:7)
- Spiritual death: Separation from God — the state of the unregenerate (Eph 2:1)
- Intermediate state (between death and resurrection):
- Believers: "To be with Christ" — conscious, blessed (Phil 1:23; Luke 23:43; 2 Cor 5:8)
- Unbelievers: Separation and awaiting judgment (Luke 16:23; 2 Pet 2:9)
- Purgatory (Catholic): No solid scriptural support; rejected by Protestantism
The Millennium — Main Positions
Premillennialism: Christ returns before the millennium and reigns 1,000 years on earth (Rev 20:1–6)
- Dispensationalism: Literal millennium with restored Israel, rebuilt Temple, OT prophecies fulfilled literally
- Historic Premillennialism: Similar, but without the Israel–Church distinction
Amillennialism: Millennium = the current Church age (from first to second coming) — the 1,000 is symbolic Christ reigns spiritually now; no literal 1,000-year reign (Augustine, Calvin, most Reformed theology)
Postmillennialism: The gospel gradually transforms the world; Christ returns after a golden age of Christianity (Puritans; Jonathan Edwards; dominionist theology)
The Tribulation and Rapture
Pretribulational Dispensationalism (popular in American evangelicalism):
- Secret rapture before the 7-year tribulation
- Israel and the Church as separate redemptive programs
Posttribulationism:
- The Church passes through tribulation; rapture and Second Coming = one event
- Position of most Reformed and historic theologians
Key texts: Matt 24; 1 Thess 4:13–18; 2 Thess 2; Rev 4–19
Final Judgment and Eternity
- Universal judgment: Every person will give account (2 Cor 5:10; Rev 20:11–15)
- Basis of judgment: Works as evidence of faith or unbelief — not the basis of salvation (Matt 25:31–46; Rev 20:12)
- Hell: Eternal separation from God (Matt 25:46; Rev 20:14–15)
- Annihilationism: The condemned are completely destroyed — debated (Clark Pinnock)
- Conscious torment: Eternal suffering — the historic majority position
- Heaven / New Creation: Face-to-face communion with God, complete restoration of creation (Rev 21–22)
🌿 Sanctification — Grace and the Christian Life
Covenant of Works vs. Covenant of Grace
Covenant of Works (pre-fall): God promises life to Adam on condition of perfect obedience (Hos 6:7)
Covenant of Grace (post-fall): God promises salvation through a Mediator — God's initiative, not man's (Gen 3:15)
All of biblical history = the unfolding of the covenant of grace through sub-covenants (Noahic, Abrahamic, Mosaic, Davidic, New).
Sanctification — How We Become Holy
- Definitive sanctification: At conversion — declared "holy" (1 Cor 6:11)
- Progressive sanctification: Ongoing transformation by the Spirit, Word, prayer, community (2 Cor 3:18; Phil 2:12–13)
- Glorified sanctification: Complete at glorification (1 John 3:2)
Perseverance of the Saints vs. Assurance
- "Once saved, always saved" — a dangerous oversimplification
- Reformed perseverance: The truly elect will persevere — cannot finally fall (John 10:28–29; Rom 8:38–39)
- Assurance rests on: God's promises + Christ's work + the Spirit's witness (Rom 8:16) + the fruit of faith (2 Pet 1:10)
- The warnings (Heb 6:4–6; 10:26) are real — addressed to those who appear to believe without truly doing so
📐 Biblical Theology vs. Systematic Theology
| Biblical Theology | Systematic Theology | |
|---|---|---|
| Approach | Traces themes through Scripture chronologically | Organizes themes from Scripture logically |
| Question | "How does revelation develop from Genesis to Revelation?" | "What does all of Scripture say about X?" |
| Strength | Respects progressive revelation; literary context | Doctrinal clarity; practical application |
| Risk | May neglect the final synthesis of doctrine | May impose external categories on the text |
| Relationship | Complementary — each feeds the other |
The great theologians of history excelled in both: Calvin, Owen, Edwards, Geerhardus Vos, Herman Bavinck.
See also: Biblical Glossary · Prophecies & Fulfillment · Biblical Characters