Abstract
This appendix explores how the Father, Son, and Holy Spirit act together in every divine operation. Classical Christian theology maintains that all external works of God (opera ad extra) are indivisible: the three persons act with one will and purpose. Yet within this unity each person performs a distinct role—source, mediator, and perfecter. By examining biblical evidence and patristic interpretation, this study shows that creation, redemption, and revelation are triune acts expressing one divine essence.
1 Introduction: Unity and Distinction
The confession of one God in three persons requires the affirmation that divine action is both unified and personalised. The early Church Fathers expressed this through the concept of perichōrēsis—mutual indwelling. Each person exists in the others without confusion or separation (Gregory of Nazianzus, Oration 31). Consequently, no act of God is performed by one person in isolation. All things are from the Father, through the Son, and by the Holy Spirit (1 Cor. 8 : 6).
2 Biblical Foundations of Co-Agency
2.1 Creation
The opening chapter of Genesis reveals all three persons:
- Father: the origin of purpose (“God said…” – Gen. 1 : 3);
- Son (Word): the mediating agent (“All things were made through Him” – John 1 : 3);
- Spirit: the life-giver (“The Spirit of God hovered over the waters” – Gen. 1 : 2).
Creation is a single act of divine will expressed through different personal functions.
2.2 Redemption
The New Testament presents salvation as equally triune:
- The Father sends the Son (John 3 : 16).
- The Son accomplishes redemption through obedience and the cross (Phil. 2 : 8).
- The Spirit applies this work to believers (John 16 : 13–15).
At Calvary, the Son “offered himself through the eternal Spirit to God” (Heb. 9 : 14): one act, three agents.
2.3 Revelation
All revelation proceeds from the Father (John 7 : 16), is embodied in the Son (John 1 : 18), and made comprehensible by the Spirit (1 Cor. 2 : 10–12). The Spirit ensures that the Word spoken by the Father and incarnate in the Son remains living and effective in the Church.
3 Distinction of Persons and Unity of Essence
The Father, Son, and Spirit are distinct in relation, not in substance. The Father begets, the Son is begotten, and the Spirit proceeds (John 15 : 26). These are eternal relations within the one divine nature (ousia). Augustine summarised: “They are each in each, and all in each, and each in all” (De Trinitate, VI.10). Distinction does not entail division; equality does not abolish order.
4 The Economic Order of Divine Action
Theologians use the term taxis (order) to describe how divine persons act outwardly:
- From the Father – the fountain of deity and will;
- Through the Son – the Word who executes the Father’s purpose;
- By the Spirit – the life-giving presence completing and applying the work.
This economic structure ensures harmony in all divine acts, while the essence remains undivided.
5 Unity of Worship and Prayer
Christian prayer mirrors divine order. Believers pray to the Father, through the Son, in the Holy Spirit (Eph. 2 : 18). The Spirit enables the cry “Abba, Father” (Rom. 8 : 15); the Son mediates access; the Father receives. Thus, every authentic prayer is participation in the triune communion.
6 The Triune Work in the Life of Believers
6.1 Salvation
Ephesians 1 : 3–14 outlines the triune pattern of redemption:
- The Father chooses (vv. 3–6);
- The Son redeems (vv. 7–12);
- The Spirit seals (vv. 13–14).
Believers live within the grace of this threefold unity.
6.2 Sanctification
The Spirit reproduces in the believer the moral likeness of Christ (Gal. 5 : 22–23). This inner renewal realises the Father’s intention and continues the Son’s mission.
6.3 Mission
The Church’s mission arises from the triune sending: the Father commissions, the Son commands, and the Spirit empowers (Matt. 28 : 19; Acts 1 : 8).
7 The Principle of Indivisible Operation
The classical axiom opera Trinitatis ad extra sunt indivisa—“the external works of the Trinity are indivisible”—states that every act of God outside Himself is performed by all three persons. Hilary of Poitiers insisted: “The Father does nothing apart from the Son, nor the Son apart from the Father; neither is the Holy Spirit separated from the unity of the divine nature” (De Trinitate, II.1). This principle preserves both unity and relational distinction.
8 Summary Table of Divine Operations
| Divine Person | Role in Divine Operation | Primary Scriptural Witness | Description |
|---|---|---|---|
| Father | Source and Initiator | John 3 : 16; Eph. 1 : 3–6 | Origin of divine will, the fountain of creation and salvation. |
| Son | Mediator and Executor | John 1 : 1–14; Col. 1 : 16–20 | Performs the Father’s will; redeems creation through incarnation and cross. |
| Holy Spirit | Perfecter and Applier | Gen. 1 : 2; Rom. 8 : 9–17 | Completes and applies the work; renews and unites all things in God. |
9 Practical and Devotional Implications
Understanding divine co-agency transforms both theology and worship:
- It prevents the separation of God’s actions into competing roles.
- It assures believers that the entire Godhead participates in their redemption.
- It grounds prayer, mission, and sanctification in divine fellowship rather than individual effort.
The triune unity becomes the model of Christian unity—distinct yet inseparable.
10 Conclusion
In every act of God—creation, redemption, revelation, and sanctification—the Father, Son, and Holy Spirit work together inseparably. Their unity of essence ensures one divine will; their personal distinctions express the richness of divine love. The Father is never without His Word; the Word is never without His Spirit; and the Spirit never acts apart from the Father and the Son.
Thus, the whole economy of salvation manifests one Name, one purpose, and one God who is blessed for ever.
References
Augustine (1991) On the Trinity (De Trinitate). Trans. E. Hill. New York: New City Press.
Basil of Caesarea (1980) On the Holy Spirit. Crestwood, NY: St Vladimir’s Seminary Press.
Gregory of Nazianzus (1994) Orations 27–31: The Theological Orations. Crestwood, NY: St Vladimir’s Seminary Press.
Hilary of Poitiers (1999) On the Trinity (De Trinitate). Washington, DC: Catholic University of America Press.
Kelly, J.N.D. (1978) Early Christian Doctrines, 5th ed. London: A & C Black.
Torrance, T.F. (1996) The Christian Doctrine of God, One Being Three Persons. Edinburgh: T&T Clark.