The Trinitarian Doctrine of Inseparable Operations

Introduction

The Doctrine of Inseparable Operations is significant in Trinitarian studies and devotion. Because God is one, He also works as one in the economy of salvation; this truth is paramount to understanding God’s work in the world and in individuals. Therefore, this paper will explore this doctrine in light of Scripture, Church history, and contemporary opinions, defining, defending, and declaring it central to the Christian Faith.

Caveats: The Immanent and Economic Trinity, Divine Simplicity, and Appropriation

Within theology, the Trinity can be understood in two ways—eternally or immanently (i.e., who God is outside of history) and economically (i.e., what God does in history)—but these two categories “do not constitute two different Godheads; rather, they are two different manners of approaching the same Godhead.”¹ While this paper will focus on the economic Trinity, the immanent Trinity will also be addressed, for the doctrine of Inseparable Operations stems from God’s unified essence, or His attribute of Divine Simplicity (i.e., He is not composed of parts but is unified). The statement underscores this connection: “‘The economic Trinity is the immanent Trinity, and vice versa.’ In other words: 1) The God who is known in the economy of salvation corresponds to the way in which God actually is… 2) The human experience of God’s action in the economy of salvation is also an experience of God’s inner history and immanent life.”² Thus, when discussing the Doctrine of Inseparable Operations, Divine Simplicity is almost always intertwined with it, as both concepts emphasize God’s unity. This connection will be further demonstrated through insights from faithful Trinitarian theologians in the subsequent sections, providing a more comprehensive definition of the topic and its historical context.

It also must be clarified that this paper will touch upon the Doctrine of Appropriation, although it will not be the paper’s primary focus. Matthew Barrett explains Appropriation well: “The word ‘appropriation’ has been used by theologians to explain how the Scriptures can speak of a particular person of the Trinity whenever an act of the Triune God is in focus. Appropriation ‘attributes an action or an effect to a divine person in a special way, without excluding the two others.’”³ In other words, Appropriation does not compromise the Trinity of its singularity, unity, or simplicity; it “does not undermine inseparability but reinforces it in every way.”⁴

With these considerations in mind, it is time to delve into the Doctrine of Inseparable Operations in greater detail.

Defining Inseparable Operations

Does each person of the Trinity have their own will? This is an important question to consider when defining Inseparable Operations, and, once again, Barrett provides an answer: “Since God has one essence, [H]e has one will… His one essence and will subsists in three [P]ersons; those three [P]ersons remain undivided due to the one, single essence and will they have in common.”⁵ Therefore, since God is one in essence and will, it makes sense that He is also one in action, work, or operation. As Augustine says, “‘The Father, and the Son, and the Holy Ghost are inseparably united in themselves’ since ‘this Trinity is one God,’ and therefore ‘all the works of the one God are the works of the Father, of the Son, and of the Holy Ghost.’”⁶ This understanding of God’s operation derived from His essence and will lays a solid foundation for recognizing how Inseparable Operations manifest in the economy of salvation. For example, Ephesians states, “In love [God] predestined us for adoption to himself as sons through Jesus Christ, according to the purpose of his will”⁷ (Eph. 1:5), and Romans similarly declares, “For all who are led by the Spirit of God are sons of God. For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, ‘Abba! Father!’” (Rom. 8:14-15). Vern Poythress explains Inseparable Operations in light of these verses:

Through Christ, [Christians] are adopted to be sons of [their] heavenly Father, so [they] have a relationship to God the Father through Christ the Son and are united to Christ through the Holy Spirit… [The] three [Persons] act in distinct ways; they are actually distinct from one another in their actions. On the other hand, they are acting together. It’s one process. It’s one reality of adoption, being, and experiencing the love of God the Father through the Son in the power of the Spirit.⁸

In other words, these passages demonstrate how God’s unified will brings about Adoption, a Trinitarian work in which the Persons act in appropriated yet unified and inseparable ways. J.I. Packer declares the Trinity’s Inseparable Operations and unified will are “the truth about God that was revealed through the words and works of Jesus, and that undergirds the reality of salvation as the New Testament sets it forth.”⁹ However, God’s unified will is not only demonstrated in Adoption.

Poythress also presents Creation as another illustration of God’s Inseparable Operations: “God the Father creates the world by speaking, and that speech, of course, is reflective of the second person of the Trinity who is the Word of God. And when God creates, the Holy Spirit is present moving over the face of the waters.”¹⁰ The same reality is expressed in this situation: The unified God acts in a singular event—Creation—yet the Persons of God are present in appropriated ways. The Trinity’s unified yet appropriated actions of Creation will be revisited in the following section.

So far, the economy of salvation, as it pertains to Adoption and Creation, has been examined. Still, stepping back from the economic Trinity and focusing on the immanent Trinity is beneficial, for the immanent Trinity also contains Inseparable Operations or, at the very least, plans for them in the economy of salvation. Packer explains this plan as the “covenant of redemption” and quotes the Westminster Confession of Faith to summarize the term:

It pleased God in [H]is eternal purpose, to choose and ordain the Lord Jesus, [H]is only-begotten Son, to be the mediator between God and man, the Prophet, Priest, and King, the Head and Savior of [H]is Church, the heir of all things, and Judge of the World: unto whom [H]e did from all eternity give a people, to be [H]is seed, and to be by [H]im in time redeemed, called, justified, sanctified, and glorified. (8.1)¹¹

More succinctly, the covenant of redemption is the Father initiating or planning salvation, the Son complying and accomplishing it, “and the Spirit executing the will of both, which is [H]is will also.”¹² Otherwise, the pactum salutis (Latin for covenant of redemption) is the intratrinitarian agreement where, as Augustine says, the Father is the Author/Architect of salvation, the Son is the Redeemer of salvation, and the Holy Spirit is the Sanctifier of salvation.¹³ Paul, in his Epistle to the Ephesians, speaks of the covenant of redemption directly: “In [the Beloved] we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace, which he lavished upon us, in all wisdom and insight making known to us the mystery of his will, according to his purpose, which he set forth in Christ as a plan for the fullness of time, to unite all things in him, things in heaven and things on earth.” (Eph. 1:7-10). This passage demonstrates God’s plan of salvation “for the fullness of time” and Christ’s propitiatory sacrifice to accomplish or purchase such salvation on behalf of His people. Undoubtedly, the immanent Trinity resolved to work inseparably in the economy of salvation. However, unfortunately, there are some people, even “Christians,” who reject this.

Defending Inseparable Operations

Returning to the Trinitarian work of Creation, many misunderstand Inseparable Operations and Appropriation. Augustine writes the following:

Some persons, however, find a difficulty in this faith; when they hear that the Father is God, and the Son God, and the Holy Spirit God, and yet that this Trinity is not three Gods, but one God; and they ask how they are to understand this: especially when it is said that the Trinity works indivisibly in everything that God works, and yet that a certain voice of the Father spoke, which is not the voice of the Son… They wish to understand how the Trinity uttered that voice which was only of the Father… Yet, otherwise, the Trinity does not work indivisibly, but the Father does some things, the Son other things, and the Holy Spirit yet others: or else, if they do some things together, some severally, then the Trinity is not indivisible.¹⁴

Augustine answers this problem in several places, yet a more explicit answer is not presented than this: “[B]ecause it is true, “I and my Father are one,” when the Father is manifested, the Son also, who is in Him, is manifested; and when the Son is manifested, the Father also, who is in Him, is manifested.”¹⁵ He also clarifies this relationship for the whole Trinity when he declares, “[I]n order to intimate the Trinity [in the Scriptures], some things are separately affirmed, the Persons being also each severally named; and yet are not to be understood as though the other Persons were excluded, on account of the unity of the same Trinity and the one substance and Godhead of the Father and of the Son and of the Holy Spirit.”¹⁶ What does this mean? Again, it means that Persons of the Trinity act together as one yet distinctly. Therefore, in answering objections to God’s Three-in-One status, Christians must acknowledge the unity of the Godhead, as they operate together inseparably, and their distinction when Scripture mentions them severally, just as Augustine does.

While Augustine’s insights are helpful, they do not answer the question explicitly regarding Creation. However, Michael Reeves speaks on the Inseparable Operations of the Trinity, saying, “[I]n Genesis 1, [God] creates through [H]is Word and [H]is Spirit… [T]he Word goes out in the power of the hovering Spirit so that on God’s Breath [H]is Word is heard” “Let there be light!” Thus, the Father creates through [H]is Word (John 1:3), the Word being [H]is executive arm.”¹⁷ Even further, Reeves clarifies, “[S]ome Scriptures speak of [C]reation as the work of the Father (it is conceived in [H]is love); others speak of [C]reation as the work of the Son ([H]e brings about [H]is Father’s will); but still others speak of it as the work of the Spirit. ‘By the [W]ord of the Lord were the heavens made, their starry host by the breath [or Spirit] of [H]is mouth’ (Ps. 33:6).”¹⁸ Reeves does a great job emphasizing the unity of the Godhead within Creation while maintaining their appropriated tasks. Another way to say this is, as Scott Swain puts it, “the Father speaks, the Son is the Father’s Word, and the Spirit is the [B]reath that bears the Father’s divine utterance in the Son and cause the things that the Father has spoken into being through the Son to be what God has called them to be.”¹⁹ This is a particularly strong understanding of the Godhead’s unity yet the Person’s distinctions within Creation.

Because the doctrine of the Trinity is so complex, it is not surprising there would be incorrect views of it, such as functional modalism and chronological modalism (Sabellianism).²⁰ The former posits that at any given moment, God functions in one of three modes—the Father, Son, or Spirit—while the latter declares God acts in these modes at different stages of history.²¹ Fundamentally the same, both views are wrong and directly contradict the Trinitarian Doctrine of Inseparable Operations, for as previously demonstrated, the Persons of the Trinity work inseparably and simultaneously according to their personalities, yet do so in a single unified act. What becomes difficult to explain is that functional modalism, similar to Augustine, appropriates the Father as Creator, the Son as Redeemer, and the Spirit as Sanctifier, but it does so because these are not inseparable works of the Trinity but because God acts as Father to create, Son to redeem, and Spirit to sanctify over time.²² There is quite a distinction between Augustine’s position and that of functional modalism. Still, improperly understood, Augustine could be called a functional modalist, a characterization he would despise, for in his eyes, the appropriated work of the Persons is simultaneous rather than sequential. This understanding safeguards the Trinity from being understood through a modalistic framework. The Baptism of Jesus shows this understanding well: “And when Jesus was baptized, immediately he went up from the water, and behold, the heavens were opened to him, and he saw the Spirit of God descending like a dove and coming to rest on him; and behold, a voice from heaven said, “This is my beloved Son, with whom I am well pleased” (Matt. 3:16-17). Not only does Jesus’ Baptism demonstrate the simultaneous presence of all three Persons, but it also highlights their inseparable work at a crucial moment in redemptive history.

Declaring Inseparable Operations

With the Doctrine of Inseparable Operations defined and defended, it is time to reflect on its significance for the Christian Life. As previously mentioned, the Baptism of Jesus plays a crucial part in the defense of Inseparable Operations, but the Baptism of believers and their offspring is also significant. In the Great Commission of Matthew 28, Jesus implores His disciples: “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age” (Matt. 28:19-20). Regarding this verse, Swain says, “[T]he three are identified with the one God, they are nevertheless distinguished from each other by their [P]ersonal names “the Father,” “the Son,” and “the Holy Spirit… [these are] mutual relations, which are ‘relations of origin.’”²³ This is important to note because, as shown, “the mutual relations between the [P]ersons of the Trinity exhibit themselves within God’s indivisible external works”²⁴ or, Barrett says, “God’s work ad extra as opposed to His work ad intra.”²⁵ Why is this important? It is essential because God’s distinction and oneness ad extra demonstrates His purpose ad intra. The Doctrine of Inseparable Operations within the economy of salvation demonstrates who He is according to eternity. Because God acts according to who He inherently is, Christians should rejoice, for their God is trustworthy and unchanging.

This is essentially what a believer or their parents declare in Baptism. The Trinitarian formula of Baptism acknowledges the same unified God who works both ad intra and ad extra.

Similarly, prayer shows the threeness of God and the Trinity’s Inseparable Operations. C.S. Lewis is helpful here. First, he posits “that theology is practical. The whole purpose for which [humans] exist is to be thus taken into the life of God.”²⁶ It is for this exact purpose Christians pray. Furthermore, Lewis clarifies:

An ordinary simple Christian kneels down to say his prayers. He is trying to get into touch with God. But if he is a Christian he knows that what is prompting him to pray is also God: God, so to speak, inside him. But he also knows that all his real knowledge of God comes through Christ, the Man who was God — that Christ is standing beside him, helping him to pray, praying for him. You see what is happening. God is the thing to which he is praying — the goal he is trying to reach. God is also the thing inside him which is pushing him on — the motive power. God is also the road or bridge along which he is being pushed to that goal. So that the whole threefold life of the three-personal Being is actually going on in that ordinary little bedroom where an ordinary man is saying his prayers. The man is being caught up into the higher kinds of life — what I called Zoe or spiritual life: he is being pulled into God, by God, while still remaining himself.

What an amazing experience for Christians! Not only do they speak to God in their little rooms, but all the Persons of the Trinity are working through and for them. Therefore, Christians must rejoice and practice the devotion of prayer all the more.

A particular prayer in the form of a poem that resonates with Lewis’ insights is John Donne’s “Holy Sonnet XIV”:

Batter my heart, three-person’d God, for you As yet but knock, breathe, shine, and seek to mend; That I may rise and stand, o’erthrow me, and bend Your force to break, blow, burn, and make me new. I, like an usurp’d town to another due, Labor to admit you, but oh, to no end, Reason, your viceroy in me, me should defend, But is captiv’d, and proves weak or untrue. Yet dearly I love you, and would be lov’d fain, But am betroth’d unto your enemy; Divorce me, untie or break that knot again, Take me to you, imprison me, for I, Except you enthrall me, never shall be free, Nor ever chaste, except you ravish me.²⁷

While Donne addresses this prayer to the one “three-person’d God,” several lines have implications for the appropriated work of the Persons. For instance, the lines, “I, like an usurp’d town to another due,” and “But am betroth’d unto your enemy; Divorce me, untie or break that knot again” bring about thoughts of Christ’s victory over the forces of evil on the Cross (Mark 3:27). Moreover, the phrases, “Take me to you, imprison me, for I, Except you enthrall me, never shall be free, Nor ever chaste, except you ravish me” demonstrate the transformation Christians undergo from slaves of sin to slaves of the Triune God. Romans 6:22, among other verses of Scripture, serves as evidence for this: “But now that you have been set free from sin and have become slaves of God, the fruit you get leads to sanctification and its end, eternal life.” Overall, this prayer is a solid model for how a Trinitarian Christian should pray, for it acknowledges the distinct Persons, their relationship with the speaker, and their unified operation of salvation and sanctification. Believers would be wise to incorporate such a style of prayer into their devotional practices.

Conclusion

In conclusion, the Doctrine of Inseparable Operations demonstrates much about God’s identity, both within Himself and how He works in the world, and how He relates to humans and His people. A reminder from Lane G. Tipton is valuable: “[N]either the undivided divine essence, nor the incommunicable personal properties, nor the peculiar modes of personal subsistence are accidental or incidental to the life of the Godhead. They are equally basic, equally fundamental, and equally ultimate in the life of the Triune God,” demonstrating that God is truly one in Being, subsisting in three Persons who work inseparably.²⁸

Bibliography

Augustine. “On The Trinity.” In Nicene and Post-Nicene Fathers. Vol. 3, St. Augustin: On the Holy Trinity, Doctrinal Treatises, Moral Treatises, edited by Philip Schaff, translated by Arthur West Haddan. Buffalo, NY: Christian Literature Company, 1887.

Barrett, Matthew. Simply Trinity: The Unmanipulated Father, Son, and Spirit. Grand Rapids, MI: Baker Books, 2021.

Donne, John. “Holy Sonnet XIV.” In John Donne Poems, edited by Sir Herbert Grierson, 358. Oxford, UK: Oxford University Press, 1933.

Lewis, C.S. Mere Christianity. 1952. Reprint, New York, NY: HarperOne, 2001.

McGrath, Alister E. Christian Theology: An Introduction. 6th ed. Hoboken, NJ: Wiley Blackwell, 2017.

Packer, J.I. Concise Theology. 1993. Reprint, Wheaton, IL: Crossway, 2020.

Poythress, Vern. “How Do All Three Persons Work Inseparably in the Works of Creation, Providence, and Redemption?” Youtube.com, February 6, 2019. https://www.youtube.com/watch?v=qjYzGQkgWv0

Reeves, Michael. Delighting in the Trinity: An Introduction to the Christian Faith. Downers Grove, IL: InterVarsity Press, 2012.

Swain, Scott. The Trinity: An Introduction. Short Studies in Systematic Theology, edited by Graham A. Cole and Oren R. Martin. Wheaton, IL: Crossway, 2020.

Tipton, Lane G. The Trinitarian Theology of Cornelius Van Til. Libertyville, IL: Reformed Forum, 2022.

Footnotes

1. Karl Rahner, qtd. in Alister E. McGrath, Christian Theology: An Introduction, 6th ed. (Hoboken, NJ: Wiley Blackwell, 2017), 308. ↩

2. Ibid. ↩

3. Gilles Emery, qtd. in Matthew Barrett, Simply Trinity: The Unmanipulated Father, Son, and Spirit (Grand Rapids, MI: Baker Books, 2021), 297. ↩

4. Barrett, 297. ↩

5. Ibid., 291. ↩

6. Augustine, qtd. in Barrett, 291. ↩

7. Unless otherwise specified, all Scripture references are to The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016). ↩

8. Vern Poythress, “How Do All Three Persons Work Inseparably in the Works of Creation, Providence, and Redemption?,” Youtube.com, February 6, 2019, 0:33–1:32, https://www.youtube.com/watch?v=qjYzGQkgWv0. ↩

9. J.I. Packer, Concise Theology (1993; repr. Wheaton, IL: Crossway, 2020), 60. ↩

10. Poythress, 1:32–2:07. ↩

11. The Westminster Confession of Faith, qtd. in Packer, 135. ↩

12. Packer, 60. ↩

13. Barrett, 305. ↩

14. Augustine, On The Trinity 1.5.8. Logos. ↩

15. Ibid., 1.9. ↩

16. Augustine, On The Trinity, 1.9.19. Logos. ↩

17. Michael Reeves, Delighting in the Trinity: An Introduction to the Christian Faith (Downers Grove, IL: InterVarsity Press, 2012), 49–50. ↩

18. Ibid., 50. ↩

19. Scott R. Swain, The Trinity: An Introduction, Short Studies in Systematic Theology, eds. Graham A. Cole and Oren R. Martin (Wheaton, IL: Crossway, 2020), 110. ↩

20. McGrath, 309. ↩

21. Ibid. ↩

22. Ibid., 309–310. ↩

23. Swain, 32. ↩

24. Ibid., 109. ↩

25. Barrett, 115. ↩

26. C.S. Lewis, Mere Christianity (1952; repr. New York, NY: HarperOne, 2001), 161. ↩

27. John Donne, “Holy Sonnet XIV,” in John Donne Poems, ed. Sir Herbert Grierson (Oxford, UK: Oxford University Press, 1933), 358. ↩

28. Lane G. Tipton, The Trinitarian Theology of Cornelius Van Til (Libertyville, IL: Reformed Forum, 2022), 69. ↩