I am currently working on an essay on the external works of the Trinity. Below is an excerpt, which focuses on the “oneness” of those external works.
Scripture repeatedly draws our attention to the connection between the oneness of God and the oneness of God’s agency in his external works. In response to God’s wonderful works in delivering Israel from Egypt, Moses and Israel exclaim, “Who is like you, O Lord, among the gods? Who is like you, majestic in holiness, awesome in glorious deeds, doing wonders?” (Exod 15:11). The Lord’s unique and unprecedented works in the exodus reveal that he alone is God (Deut 4:32-35). In similar fashion, Isaiah appeals to God’s singular work of creation (Isa 44:24) as well as his singular works of providence to demonstrate the singularity of God: “I am the Lord, and there is no other, besides me there is no God; I equip you, though you don’t know me, that people may know, from the rising of the sun and from the west, that there is none besides me; I am the Lord, there is no other. I form light and create darkness; I make well-being and create calamity; I am the Lord, who does all these things” (Isa 45:5-7). Psalm 86:8 draws the common prophetic conclusion: “There is none like you among the gods, O Lord, nor are there any works like yours.” What prophets proclaim, apostles confirm. The oneness of God’s being entails the oneness of God’s agency, and vice-versa. Though the New Testament, like the Old Testament, acknowledges the existence of many supernatural beings, called “gods” by religious custom, it confesses the absolute uniqueness of the Lord and his agency: “For although there may be so-called gods in heaven or on earth—as indeed there are many ‘gods’ and many ‘lords’—yet for us there is one God, the Father, from whom are all things and for whom we exist, and one Lord, Jesus Christ, through whom are all things and through whom we exist” (1 Cor 8:5-6; Gal 4:8; Eph 4:4-6). According to the universal testimony of Holy Scripture, the Lord alone is God, the Lord alone does wondrous things.
God’s sovereign agency is one in an absolute sense; it is not one of anything. Transcending all creaturely agencies (Eph 4:6; James 1:17), God’s supreme and sovereign agency is uniquely God’s: “You who have done great things, O God, who is like you?” (Ps 71:19; Exod 15:11; Ps 113:5; Isa 40:25-26). God’s “ways” are not our “ways” (Isa 55:8). God’s sovereign agency is unbounded and independent (Isa 40:12-14; Job 22:2-3; 35:7; 41:11; Rom 11:33-35), simple (James 1:5; 1 John 1:5) and unchanging (James 1:17), perfectly wise (Ps 104:24) and utterly generous (Ps 145:9; James 1:17-18), always faithful (Ps 25:10) and altogether righteous (Ps 92:15), absolutely free and absolutely effective: “Our God is in the heavens; he does all that he pleases” (Ps 115:3). God in his external works is God: singular, supreme, and sovereign, infinite and independent, simple and unchanging, all-wise, all-good, all-powerful. “Holy is he!” (Ps 99:3).
God’s singular sovereign agency, furthermore, is the “total cause” of all creatures: “From him and through him and to him are all things” (Rom 11:36; 1 Cor 8:6; 12:4-6; Eph 4:6). In more technical idiom, God is the first, formal, and final cause of creatures. We may more fully appreciate this claim by considering how God’s status as the “total cause” of all things addresses three questions: Who causes all things to be? How does he cause all things to be? And why does he cause all things to be? As we will see, in each instance, the answer to these questions is “God.”
Who causes all things to be? God is the first or efficient cause of all things. To describe God as the first and efficient cause of all things is to ascribe absolute primacy to God with respect to the creature’s being and activity. He is “the alpha,” “the first” (Rev 1:8, 17; Rev 22:13). As the first cause of all things, divine causality is “above” all creaturely being and causality and, in that way, operative “through” all creaturely being and causality (1 Cor 12:6; Eph 4:6; James 1:17). God is not the first in a series of finite causes. God is a transcendent cause. God is the reason a series of finite causes exists, and he is the reason a series of finite causes continues to work. Consequently, the relationship between the primary divine cause and secondary creaturely causes is asymmetrical. Secondary causes depend wholly upon God for their being and operation, but God does not depend upon them: “Who has known the mind of the Lord, or who has been his counselor? Or who has given a gift to him that he might be repaid?” (Rom 11:34-35; Acts 17:25). The answer is “no one”: “From him … are all things” (Rom 11:36; 1 Cor 8:6). Moreover, because God radically transcends the order of created being and operation, and because created causes depend wholly upon God for their being and operation, the relationship between primary and secondary causes is non-competitive in nature. There is no “zero-sum game” between primary and secondary causes because primary and secondary causes do not compete for the same ontological, operational space. God’s agency does not compete with that of creatures, it enables and empowers the agency of creatures (Gen 1:11; Ps 104:30; Isa 42:5). His being and agency is the reason for, the productive source of their being and agency. Because God works, creatures work (1 Cor 12:4-6).
How does God cause all things to be? Not only is God the first and efficient cause of all created being and agency, he is also the formal or exemplary cause of all created being and agency. “Through him … are all things” (Rom 11:36; 1 Cor 8:6). To the affirmation that God alone causes all things to be and to act, we add the affirmation that God by himself causes all things to be and to act: “I am the Lord, who made all things, who alone stretched out the heavens, who spread out the earth by myself” (Isa 44:24). God requires no assistance in causing all things to be, in causing all things to act. He requires no counselors because he acts by his own unfathomable wisdom (Isa 40.13-14; Jer 10:12; Prov 3:19; Rom 11:33-34). He requires no motivation because he acts by his own boundless generosity (Exod 33:19; Rom 11:35; James 1:5, 17-18). He requires no helpers because he acts by his own infinite power (Isa 40:25-31; Rom 11:36; 1 Cor 12:6). Relevant here too is Scripture’s claim that God acts by his Word and Spirit (Genesis 1; Ps 33:6, 9; 104:30; Isa 42:5; 55:11). To say that God creates and moves all things by his sovereign Word and Spirit is just another way of saying that God creates and moves all things by himself, a point that holds great significance for trinitarian theology.
God’s status as the formal or exemplary cause of all created being and agency is the death-knell to the Platonic and Neoplatonic ideas that God depends on an eternal realm of forms for guidance or that God’s relation to the world must be “buffered” by a semi-divine Logos and World Soul. Not only is God solely responsible for the fact that creatures are and that creatures act. As the formal cause of all creatures, God also is solely responsible for what creatures are and how creatures act. God is the Father from whom every family in heaven and on earth is named (Eph 3:14-15), who assigns creatures their various natures by his own divine Word in accordance with his own divine wisdom (Gen 1:3ff; Ps 104:24). Moreover, though God sometimes acts immediately in the world, apart from secondary causes (Gen 1:1; Ps 33:9; Isa 44:24; Hos 1:7; Gal 4:4-7), God more usually acts mediately by means of secondary causes (Gen 1:11, 24; Eph 4:6; 1 Cor 12:4-6). Even then, God always acts intimately in the world. The one who is operative through all things is operative in all things (Eph 4:6; 1 Cor 12:6): “even when he employs means he nonetheless provides for all things directly, deeply within and without depending on the middle causes through which he operates, since he is directly at work in all of them, is always present to them, and reveals his own special power through them.”
Why does God cause all things to be? God produces the being and activity of creatures for many different reasons. Sometimes God’s reasons for acting relate to creaturely reasons for acting as root to fruit, the latter being the “fruit of the Spirit” (Gal 5:22; Isa 42:5; Psalm 104:30; James 1:17-18). Other times God’s reasons for acting oppose and overrule creaturely reasons for acting (Gen 50:20; Rom 1:24, 26, 28). Though the creature’s ability to form reasons for action, and also to carry out those actions, depends wholly on God’s agency (Isa 45:7; Lam 3:33-38), to the extent that those reasons and actions oppose God’s moral will, their source must be traced exclusively to the fallen creature rather than God (Gal 5:19; James 1:13-15). Nevertheless, to speak, as Scripture does, of God as the final cause of all things, is to identify Godas the ultimate reason God does all he does: “to him are all things” (Rom 11:36; 1 Cor 8:6). The ultimate end of God’s royal economy, above and beyond all other ends, governing all other ends, is God. He is the “omega,” the “last” (Rev 1:8, 17; 22:13). What might this mean?
To describe God as the final cause of God’s agency is not to say that God is the product of the divine economy, contrary to every Hegelian nightmare. Nor is it to say that God acquires something from the divine economy. Far from it, God’s royal economy is the product of God’s absolute generosity, wherein God is absolute benefactor, whereby God receives no benefit (1 Chron 29:10ff; Job 22:2-3; 35:7; 41:11; Isa 40:15-17, 25-31; Acts 17:25; Rom 11:35-36; James 1:17-18). As Thomas Aquinas observes, in the divine economy, God is “the most perfectly liberal giver, because God does not act for his own profit, but only for his own goodness,” more specifically, to communicate his goodness to creatures. To say, then, that God is the final cause of all things is to say that, within God’s royal economy, God’s goodness is the supreme reason God acts. God knows and loves himself as supreme good, as supreme blessing, and God desires to share himself with rational creatures, whom he orders and moves to himself as their supreme good and final end (Deut 6:4; Ps 27:4; John 17:3, 24-26; Rom 8:28-29). “Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places … to the praise of his glorious grace” (Eph 1:3, 6)!
 Craig Carter, Contemplating God with the Great Tradition, 126-39.
 Thomas Aquinas, ST, I, Q 44, art. 4, ad 4. On this topic more fully, see Andrew Davison, Participation in God: A Study in Christian Doctrine and Metaphysics (Cambridge: Cambridge University Press, 2019). On the use of prepositions (e.g., from, through, to, etc.) in discussions of divine causality in Greco-Roman philosophy, Judaism, and the New Testament, see Robert M. Grant, “Causation and ‘The Ancient World View’,” JBL 83 (1964): 34-40; Gregory Sterling, “Prepositional Metaphysics in Jewish Wisdom Speculation and Early Christian Liturgical Texts,” The Studia Philonica Annual 9 (1997): 219-38; and Orrey McFarland, “Divine Causation and Prepositional Metaphysics in Philo of Alexandria and the Apostle Paul,” in Joseph R. Dodson and Andrew W. Pitts, ed., Paul and the Greco-Roman Philosophical Tradition (London: T & T Clark, 2017), 117-34.
 Edward Feser, Five Proofs of the Existence of God (San Francisco: Ignatius, 2017), 155.
 Kathryn Tanner, God and Creation in Christian Theology.
 Affirming primary divine causality therefore does not require denying secondary creaturely causality. Secondary causes are true causes, contra, for example, the occasionalism of Jonathan Edwards.
 Thomas Aquinas, John, 1:33.
 Irenaeus, Against Heresies 2.7.5; Cyril of Alexandria, Against Julian, 8.26.
 Maximos Constas, “Maximus the Confessor, Dionysius the Areopagite, and the Transformation of Christian Platonism”; Davison, Participation in God, chap. 4.
 Synopsis Purioris Theologiae, 11.15.
 Contra David Kelsey, Human Anguish and God’s Power, chap. 6.
 Thomas Aquinas, ST, I, Q 44, art. 4, ad 1.
 Thomas Aquinas, ST, I, Q 44, art. 4, resp. So WCF 2.2.
 Philip J. Donnelly, “Saint Thomas and the Ultimate Purpose of Creation.”