Theology Proper & Christology in Reformed Covenant Perspective

By Adam Malin Date: August 25, 2025

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Covenant Theology does not overlay Scripture with a foreign scheme; it exposes the frame Scripture itself declares. Thus theology proper (who God is) and Christology (who the Mediator is) cohere with salvation by grace alone. Because the one God is simple and the Trinity works indivisibly ad extra, the decree of the Father, the redemption accomplished by the Son, and the application by the Spirit intend and secure the same people. Scripture joins these without remainder: those foreknown and predestinated are effectually called, justified, and glorified (Romans 8:29–30); the Son has authority to give eternal life “to as many as thou hast given him” (John 17:2, 9); and the Spirit sanctifies those chosen “to salvation through sanctification of the Spirit and belief of the truth,” by the gospel call (2 Thessalonians 2:13–14). Therefore New-Covenant promises are effectual realities, not bare offers, for God writes His law on the heart, ensures saving knowledge of Himself, and remembers sin no more (Hebrews 8:10–12; Jeremiah 31:33–34). This summary accords with the Westminster Confession of Faith, especially chapters II–III and VIII.

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I. Theology Proper — Who God Is

1) God’s Being: Spirit, One, Simple

Spirit & Unity. Scripture declares: “God is a Spirit: and they that worship him must worship him in spirit and in truth” (John 4:24). The Shema establishes the unity of the Godhead: “Hear, O Israel: The LORD our God is one LORD” (Deuteronomy 6:4). The apostolic witness maintains both truths together—one God in three Persons, of one substance, power, and eternity (Matthew 28:19; 2 Corinthians 13:14; compare Westminster Confession of Faith II.3).

Simplicity (no competing attributes). Scripture teaches that God is without parts and passions and therefore without inner conflict (James 1:17; compare Westminster Confession of Faith II.1). His counsel and goodness are one undivided perfection: “My counsel shall stand, and I will do all my pleasure” (Isaiah 46:10); He “worketh all things after the counsel of his own will” (Ephesians 1:11); and “a God of truth and without iniquity, just and right is he” (Deuteronomy 32:4). Therefore the divine decree never clashes with divine goodness; what He wills, He wisely and holily wills.

Covenantal implication. Because the undivided God acts indivisibly, the Trinity’s external works are one. The same electing counsel of the Father is the scope of the Son’s definite atonement and the Spirit’s effectual application (John 6:37–39; John 10:11, 15, 26–28; Romans 8:29–30; 2 Thessalonians 2:13–14). Hence the covenant of grace, administered in promise and fulfillment, secures its heirs rather than leaving salvation to the contingencies of human will (Jeremiah 31:33–34; Hebrews 8:10–12; compare Westminster Confession of Faith III.6; VII; VIII.8).

2) Aseity, Eternity, Omnipresence, Omniscience, Omnipotence

Aseity. Scripture denies all creaturely dependence in God: “Neither is worshipped with men’s hands, as though he needed any thing” (Acts 17:25). He has “life in himself” (John 5:26).

Eternity. God is “from everlasting to everlasting” (Psalm 90:2) and “the King eternal, immortal, invisible” (1 Timothy 1:17).

Omnipresence. No creature can flee His presence: “Whither shall I go from thy spirit? or whither shall I flee from thy presence?” (Psalm 139:7–10). “Do not I fill heaven and earth? saith the LORD” (Jeremiah 23:23–24).

Omniscience. “God… knoweth all things” (1 John 3:20); “all things are naked and opened unto the eyes of him” (Hebrews 4:13).

Omnipotence. He is “the Almighty God” (Genesis 17:1), and “with God all things are possible” (Matthew 19:26).

Doctrinal synthesis. These incommunicable perfections, confessed by the Church, ground providence and grace: the immutable, most holy God freely decrees whatsoever comes to pass without becoming the author of sin (James 1:13; Acts 2:23; Westminster Confession of Faith III.1), upholds and orders all things (Hebrews 1:3; Westminster Confession of Faith V.1), and infallibly brings His covenant to its consummation in Christ the Mediator (Ephesians 1:9–10; Hebrews 9:15; Westminster Confession of Faith VIII.1, 5).

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Hermeneutic note (apostolic method): Scripture interprets Scripture. The New Testament reads the promises to Abraham and the New Covenant in Christ as one covenant of grace across redemptive history, with Christ as the promised Seed and sole Mediator; the shadows yield to the substance, and the types to the antitype (Galatians 3:16, 29; Colossians 2:17; Hebrews 7:18–19; 10:10–14, 18). This apostolic reading explains why the grace promised is the grace effectually given.

3) Immutability and Impassibility

Immutability. Scripture declares the unchangeableness of God’s being and counsel: “I am the LORD, I change not” (Malachi 3:6); “with whom is no variableness, neither shadow of turning” (James 1:17). The apostolic witness names “the immutability of his counsel” as the ground of strong consolation to the heirs of promise (Hebrews 6:17–18). The same certainty is confessed in the Mediator: “Jesus Christ the same yesterday, and to day, and for ever” (Hebrews 13:8; Psalm 102:26–27).

Impassibility (not subject to creaturely fluctuation). God is not a man to lie or repent (Numbers 23:19; 1 Samuel 15:29). Such texts exclude volatility and creaturely passions in God, while maintaining the Creator–creature distinction: men are “of like passions” (Acts 14:15), but God is not. When Scripture speaks of God “repenting” (e.g., Genesis 6:6), it speaks after the manner of men to reveal a true change in His works ad extra, not a change in His being or decree; texts that ascribe immutability interpret the anthropopathic language (Numbers 23:19; 1 Samuel 15:29; James 1:17).

Clarification. Love, mercy, justice, and wrath are perfections of God’s simple, unchanging being, not fluctuating moods (Exodus 34:6–7; Psalm 5:4–5). Impassibility denies creaturely changeability, not divine affection. By this immutability the covenant promises stand sure: “the gifts and calling of God are without repentance” (Romans 11:29); He will “not turn away from them, to do them good” (Jeremiah 32:40). Thus the New Covenant’s efficacy flows from who God is (Hebrews 8:10–12).

4) Moral Perfections

“The LORD, The LORD God, merciful and gracious, longsuffering, and abundant in goodness and truth” (Exodus 34:6–7). “There is none holy as the LORD” (1 Samuel 2:2). He is “a God of truth… just and right is he” (Deuteronomy 32:4). “God is love” (1 John 4:8), and “God is light, and in him is no darkness at all” (1 John 1:5). These perfections are harmonized in the cross, where God is “just, and the justifier of him which believeth in Jesus” (Romans 3:26). By the apostolic method, the Servant’s substitution satisfies justice and secures mercy for the elect (Isaiah 53:5–6, 11; Ephesians 5:25).

5) The One Will of God: Decree and Command

One will, two respects. Scripture distinguishes without dividing: the decretive (secret) will and the preceptive (revealed) will. “The secret things belong unto the LORD our God: but those things which are revealed belong unto us… that we may do all the words of this law” (Deuteronomy 29:29). God “declaring the end from the beginning… My counsel shall stand” (Isaiah 46:10); He “worketh all things after the counsel of his own will” (Ephesians 1:11; Daniel 4:35; Psalm 115:3). Yet He commands what is right and holds creatures responsible (Matthew 7:21; 1 Thessalonians 4:3).

God not author of sin; compatibilism affirmed. God “cannot be tempted with evil, neither tempteth he any man” (James 1:13). Nevertheless, Scripture asserts both meticulous providence and genuine human agency: Christ was delivered up “by the determinate counsel and foreknowledge of God,” and yet “ye… have taken, and by wicked hands have crucified and slain” (Acts 2:23; see also Acts 4:27–28). Joseph’s brothers “meant evil,” but “God meant it unto good” (Genesis 50:20). Even the casting of the lot is disposed by the LORD (Proverbs 16:33). By covenantal continuity, the same decree includes the effectual means—new heart and perseverance—so that what God commands in the New Covenant He also causes (Ezekiel 36:26–27; John 6:37–39; Romans 8:29–30; Philippians 1:6).

6) The Holy Trinity and Inseparable Operations

The Church is baptized “in the name of the Father, and of the Son, and of the Holy Ghost” (Matthew 28:19). The Son declares, “I and my Father are one” (John 10:30); “what things soever he [the Father] doeth, these also doeth the Son likewise” (John 5:19); “the Father that dwelleth in me, he doeth the works” (John 14:10). The apostolic pattern ascribes diverse operations in one and the same divine act—“diversities of gifts, but the same Spirit… the same Lord… the same God which worketh all in all” (1 Corinthians 12:4–6).

Apostolic and covenantal upshot. The external works of the Trinity are indivisible and ordered: from the Father, through the Son, by the Spirit (Ephesians 2:18). Thus election, redemption, and application are one undivided work with personal properties: the Father chose a people (Ephesians 1:3–6), the Son redeemed the same by His blood (Ephesians 1:7; John 17:2, 9; John 10:11, 15, 27–29), and the Spirit effectually calls, seals, and indwells them unto the inheritance (Ephesians 1:13–14; Titus 3:5–6). Ephesians 1:3–14 sets this single, triune work in doxological sequence, confirming that the covenant of grace is effectual in all its parts.

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II. Christology — Who the Mediator Is

1) One Person, Two Natures (True God and True Man)

Definition. Scripture teaches that the eternal Son assumed a true human nature, so that the one Person, Jesus Christ, subsists “in two whole, perfect, and distinct natures, the Godhead and the manhood, without confusion, without change, without division, without separation.”

Deity. “The Word was God” (John 1:1); “Christ came, who is over all, God blessed for ever” (Romans 9:5); “in him dwelleth all the fulness of the Godhead bodily” (Colossians 2:9); “God was manifest in the flesh” (1 Timothy 3:16).

Humanity. “The Word was made flesh” (John 1:14); He “likewise took part of the same” (Hebrews 2:14); “in all things it behoved him to be made like unto his brethren” (Hebrews 2:17); He “increased in wisdom and stature” (Luke 2:52). The apostolic writers therefore confess one Mediator who is true God and true Man (1 Timothy 2:5).

Covenantal import. As the last Adam and federal Head, He fulfills the covenant of works on behalf of His people and mediates the covenant of grace as its Surety (Romans 5:18–19; Hebrews 7:22; 9:15).

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2) Two Wills (Dyothelitism) in Perfect Harmony

Scripture distinguishes the natural human will of Christ from the divine will, yet without personal division: “Not my will, but thine, be done” (Luke 22:42). The incarnate Son came “not to do mine own will, but the will of him that sent me” (John 6:38), fulfilling the prophetic word, “Lo, I come… to do thy will, O God” (Hebrews 10:7). Thus the human will of Christ is impeccably aligned to the divine will, ensuring an obedience competent to redeem.

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3) Communicatio Idiomatum (Predication to the Person)

Because properties are predicated of the Person subsisting in two natures, Scripture can say, “the church of God, which he hath purchased with his own blood” (Acts 20:28), and that rulers “crucified the Lord of glory” (1 Corinthians 2:8). This does not confuse or change the natures (John 1:14; Hebrews 2:14; Colossians 2:9); rather, it ascribes the work to the one Person who acts according to either nature as fitting.

Guardrail. What is proper to one nature is not transferred to the other; yet the Person is the common subject of all the Mediator’s acts.

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4) The Extra Calvinisticum (The Son Never Confined)

In the incarnation the eternal Son truly inhabits the assumed humanity, yet is never circumscribed by it according to His divine nature. Even as He walked on earth, “by him all things consist” (Colossians 1:17) and He was “upholding all things by the word of his power” (Hebrews 1:3). Thus He can say the “Son of man… is in heaven” (John 3:13). The apostolic method thereby preserves the infinity of the Logos while confessing the reality of the flesh.

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5) Christ’s Priestly Office: Sacrifice and Intercession Coextensive

Scripture unites oblation and intercession in one priestly work for one people: “It is Christ that died… who also maketh intercession for us” (Romans 8:34); “he ever liveth to make intercession for them” (Hebrews 7:25). The same “them” are those for whom the offering was made: “by his own blood… having obtained eternal redemption for us” (Hebrews 9:12); “by one offering he hath perfected for ever them that are sanctified” (Hebrews 10:14).

Extent defined by covenant election. The Scriptures delimit the priestly scope: “he shall save his people from their sins” (Matthew 1:21); “the good shepherd giveth his life for the sheep… I lay down my life for the sheep” (John 10:11, 15, 27–29); “Christ also loved the church, and gave himself for it” (Ephesians 5:25). In His High Priestly prayer, the Mediator intercedes not for the world indiscriminately but for those given Him by the Father (John 17:2, 9). By covenantal coherence, sacrifice and intercession are coextensive, establishing definite atonement and effectual application.

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6) Active and Passive Obedience

Active obedience (law-keeping for His people). Being “made under the law” (Galatians 4:4), the second Adam rendered perfect, personal, and perpetual obedience. Thus “by the obedience of one shall many be made righteous” (Romans 5:19). He fulfilled all righteousness (Matthew 3:15) and was “without sin” (Hebrews 4:15).

Passive obedience (suffering the curse for His people). He became “obedient unto death, even the death of the cross” (Philippians 2:8). “The LORD hath laid on him the iniquity of us all… by his knowledge shall my righteous servant justify many; for he shall bear their iniquities” (Isaiah 53:6, 11). He was “made a curse for us” (Galatians 3:13) and “made… to be sin for us… that we might be made the righteousness of God in him” (2 Corinthians 5:21).

Result: full righteousness imputed, full guilt removed. The righteousness of Christ is counted to believers for justification, while their sins are imputed to Christ and borne away (Romans 3:21–26; 4:5–8; Hebrews 10:10–14). Thus the covenant of grace provides not only pardon but a positive title to life in the Second Adam, in accord with the Westminster doctrine of justification and the perseverance of the saints (Romans 8:1, 30; Hebrews 7:25).

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III. Covenant Theology—The Logic Engine of Soteriology

1) The Covenant of Redemption (Pactum Salutis)

Scripture identifies an eternal counsel wherein the Father gives a people to the Son, the Son undertakes their redemption, and the Spirit effectually applies the purchased salvation. “All that the Father giveth me shall come to me… of all which he hath given me I should lose nothing” (John 6:37, 39). The Mediator has authority “to give eternal life to as many as thou hast given him” (John 17:2; see also John 17:6, 9, 24). This intra-trinitarian pact appears in promise and fulfillment: “Lo, I come… to do thy will, O God” (Psalm 40:7–8; Hebrews 10:5–10); “it pleased the LORD to bruise him… he shall see of the travail of his soul, and shall be satisfied” (Isaiah 53:10–12). As Surety of the covenant, Christ secures the inheritance for those given Him (Hebrews 7:22; Ephesians 1:3–7; 2 Timothy 1:9; Titus 1:2). By apostolic method, this pact grounds definite atonement and effectual calling: the same people are given, redeemed, and kept (John 6:37–39; John 10:27–29).

2) Federal Headship: Adam and Christ

The covenantal structure of Scripture sets two representatives before mankind. In Adam, sin and death enter for all he represents; in Christ, righteousness and life are secured for all He represents. “By one man sin entered into the world, and death by sin… so by the obedience of one shall many be made righteous” (Romans 5:12, 19). “For as in Adam all die, even so in Christ shall all be made alive” (1 Corinthians 15:22; see also 1 Corinthians 15:45–49). This federal headship explains imputation: Adam’s guilt to his seed, Christ’s righteousness to His seed (Romans 5:15–18; 2 Corinthians 5:21).

3) New-Covenant Efficacy (not mere offer)

The New Covenant, established in Christ’s blood, effectually gives what it promises to its heirs. God writes His law within, grants saving knowledge, and decisively forgives sins: “I will put my law in their inward parts… I will forgive their iniquity” (Jeremiah 31:33–34); “A new heart also will I give you… and cause you to walk in my statutes” (Ezekiel 36:26–27). Christ identifies His death as the covenant-making act: “This cup is the new testament in my blood” (Luke 22:20). The apostolic exposition confirms efficacy: “I will put my laws into their mind” (Hebrews 8:10–12), and “by one offering he hath perfected for ever them that are sanctified” (Hebrews 10:14; see 10:15–18). Thus the gospel is freely offered to all (Isaiah 55:1; Revelation 22:17), while the covenant promises are effectually bestowed upon the elect (John 6:37; Acts 13:48).

4) Calling, Faith, and Preservation Flow from Who God Is and Who Christ Is

Effectual calling arises from the Father’s sovereign drawing, grounded in the Son’s redemption and applied by the Spirit: “No man can come to me, except the Father which hath sent me draw him… except it were given unto him of my Father” (John 6:44, 65). Regeneration and faith are of God: believers are “born… of God” (John 1:13), and “as many as were ordained to eternal life believed” (Acts 13:48). The golden chain secures the whole salvation: “Whom he did predestinate, them he also called… justified… glorified” (Romans 8:30). Preservation is the Mediator’s charge and the Spirit’s sealing: “They shall never perish, neither shall any man pluck them out of my hand” (John 10:28–29); believers are “kept by the power of God through faith unto salvation” (1 Peter 1:5; see also Philippians 1:6; 1 Thessalonians 5:23–24; Jude 24). The covenantal logic therefore yields the doctrines of grace: unconditional election, effectual calling, persevering grace—in Christ the Mediator (Ephesians 1:3–14).

Foreknowledge as fore-love. In Romans 8:29–30, “whom he did foreknow” identifies the objects of God’s prior love and choice; the same persons are predestinated, called, justified, and glorified. The biblical usage confirms a relational knowing—“You only have I known of all the families of the earth” (Amos 3:2)—and guards against reading bare foresight of human acts into the text (Romans 11:2; John 10:14, 27).

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IV. Scope and Effect — A Reader’s Map for “All/World” and the Free Offer

Scope (breadth). Scripture often uses “all” and “world” to denote all kinds without exception of nation, rank, or class. “There went out a decree from Caesar Augustus, that all the world should be taxed” (Luke 2:1)—the Roman world in its breadth, not every individual. Prayer is urged “for kings, and for all men,” because God “will have all men to be saved”—that is, men of every station and sort—and Christ “gave himself a ransom for all” (1 Timothy 2:1–6). By the apostolic method, the promised blessing extends beyond Israel to the nations: Christ will “draw all men” (all kinds, Jew and Gentile) unto Himself (John 12:32; compare John 11:51–52; Revelation 5:9; 7:9).

Effect (efficacy). The same Scripture that proclaims global scope asserts definite efficacy: the Mediator actually saves His people. “He shall save his people from their sins” (Matthew 1:21). “The good shepherd giveth his life for the sheep” (John 10:11, 15); those sheep hear His voice and are kept to the end (John 10:27–29). Death and intercession are coextensive: those for whom He died are those for whom He intercedes and whom He secures (Romans 8:33–34; Hebrews 7:25; 9:12, 24–28; John 17:2, 9). “By one offering he hath perfected for ever them that are sanctified” (Hebrews 10:14).

Sincere offer. The gospel is freely and truly offered to all without distinction. “Whosoever believeth in him should not perish” (John 3:16). “Whosoever will, let him take the water of life freely” (Revelation 22:17). The call is universal and sincere (Isaiah 55:1), while the coming is certain for those given by the Father: “All that the Father giveth me shall come to me” (John 6:37, 44). Thus Scripture preserves both the well-meant offer to every hearer and the effectual grace that brings the elect infallibly to Christ.

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V. Romans 9—Mercy and Hardening on God’s Purpose

Thesis. The chapter vindicates the faithfulness of God’s word by distinguishing between Israel after the flesh and the Israel of promise: “They are not all Israel, which are of Israel” (Romans 9:6–8). Election is unconditional: before birth or works, “that the purpose of God according to election might stand,” it was said, “The elder shall serve the younger… Jacob have I loved, but Esau have I hated” (Romans 9:11–13).

Divine freedom and justice. God announces His sovereign liberty: “I will have mercy on whom I will have mercy” (Romans 9:15). Consequently, salvation is “not of him that willeth, nor of him that runneth, but of God that sheweth mercy” (Romans 9:16). God hardens judicially whom He will (Romans 9:17–18), yet creaturely guilt remains: the same section upholds human responsibility even as it magnifies sovereign grace (compare Acts 2:23; Genesis 50:20).

Potter and clay; vessels of mercy. The apostolic argument silences murmuring: “Nay but, O man, who art thou that repliest against God?” (Romans 9:20). God endures “vessels of wrath fitted to destruction” to make known “the riches of his glory on the vessels of mercy, which he had afore prepared unto glory” (Romans 9:22–23). The result is a remnant according to election, including the calling of the Gentiles (Romans 9:24–29; 11:5–7). Thus Romans 9 grounds salvation in God’s purpose, not in human will, and establishes the doctrines of unconditional election and effectual grace.

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VI. Doctrine to Life — Assurance, Duty, Invitation

Assurance. The immutability of God’s purpose and the completeness of Christ’s work secure believers. “If God be for us, who can be against us?” (Romans 8:31–39). None can lay anything to the charge of God’s elect; the risen Christ intercedes (Romans 8:33–34). The Shepherd’s hand guarantees perseverance (John 10:27–29); believers are “kept by the power of God through faith unto salvation” (1 Peter 1:5; Philippians 1:6).

Duty. The same decree appoints the means. Christ commands, “Go ye into all the world, and preach the gospel to every creature” (Mark 16:15). Faith comes by hearing the Word preached (Romans 10:14–17). The ministerial pattern embraces toil “for the elect’s sakes” as the ordained instrument of gathering Christ’s sheep (2 Timothy 2:10; Acts 18:9–10). In the church, the sacraments confirm the promise to faith as covenant signs (Matthew 28:19; 1 Corinthians 11:23–26; compare Romans 4:11).

Invitation. The warrant to come is the command and promise of God. “Him that cometh to me I will in no wise cast out” (John 6:37). Therefore every hearer is summoned to repent and believe the gospel today (Mark 1:15; Acts 17:30–31), assured that Christ receives all who come and that all whom the Father gave will certainly come.

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Key Terms (brief, reader-friendly)

• Simplicity. Scripture teaches that God is without parts or inner tension; His attributes are one in His essence, so His counsel and goodness are undivided (Isaiah 46:10; Deuteronomy 32:4; James 1:17).
• Impassibility. God does not change or undergo creaturely passions; His holy love, truth, and justice are constant perfections of His unchanging being (Malachi 3:6; Numbers 23:19; 1 Samuel 15:29; Exodus 34:6–7; James 1:17).
• Dyothelitism. In the one Person of Christ there are two natural wills—divine and human—in perfect harmony, the human will invariably consenting to the divine (Luke 22:42; John 6:38; Hebrews 10:7).
• Communicatio idiomatum. Predication is to the Person of the incarnate Son (e.g., “the church of God… purchased with his own blood”), without confusing or changing the divine and human natures (Acts 20:28; John 1:14; Colossians 2:9; Hebrews 2:14).
• Inseparable operations. The Trinity acts undividedly toward creation and redemption—from the Father, through the Son, by the Spirit—while the personal properties remain distinct (John 5:19; Matthew 28:19; 1 Corinthians 12:4–6; Ephesians 2:18).

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These terms serve as a study companion to John 6; Romans 8–9; Hebrews 7–10; and Jeremiah 31 with Ezekiel 36. Read with the apostolic method: the same Scriptures hold forth the sincere, universal call—“whosoever believeth” and “whosoever will” (John 3:16; Revelation 22:17)—and the definite, effectual redemption of Christ for His people, whose justification and preservation rest on His death and intercession (John 10:11, 27–29; Romans 8:33–34), unto “the praise of the glory of his grace” (Ephesians 1:6).