The Splendor Of The Three-In-One God: The Necessity And Mystery Of The Trinity (Part Two)

by on November 28, 2025

The Mystery of the Trinity

“So the Father is God, the Son is God, and the Holy Ghost is God. And yet they are not three Gods, but one God” (Athanasian Creed). How can God be truly one and also three distinct, co-eternal subsistences or persons is a mystery; and yet we are bound to say that he is. To confess these truths is to commit oneself to a great and glorious mystery—that is, something which is necessarily true but which transcends our ability to explain fully.1

In this case, then, we must repudiate the root of the Arian heresy: rationalism, the notion that one should believe only that which one can comprehend entirely. With Athanasius, we know that if “there was when the Son was not,” the Son could never be a Savior. He also knew that we can confess Jesus to be “very God of very God” only if God is triune; otherwise we are polytheists. “So we are forbidden by the catholic religion, to say, There be three Gods, or three Lords” (Athanasian Creed).

As Trinitarians we also acknowledge that it is possible to apprehend revealed truths about God and to develop them, but it is not possible to comprehend him in our formulae. Therefore, it is impossible to remove mystery from the Trinity and remain Christian. At the same time, it is also evident that Christianity is a theological religion. That is to say, it is not sufficient to quote Scripture in the face of heresy, but rather we are morally obligated not only to read Scripture carefully, but also to assemble its truths, to make good and necessary deductions from scriptural truth to edify God’s people, and to array those truths against unbelief.

For example, our Trinitarianism separates us utterly from unbelief. There is no other article of the Christian faith which so alienates unbelievers as our claim that there is one God in three persons. When we come to the doctrine of the Trinity, we Christians realize that we are completely dependent upon God’s Word for saving knowledge of God. Since the patristic-creedal period, perhaps no theologian has meditated on the Trinity more profitably than John Calvin (1509–64).2 With the breakup of the medieval church, the sixteenth century was littered with sects including anti-trinitarians. Calvin responded to the Unitarians by defending both God’s essential simplicity (God is one) and his tri-personality or tri-subsistence.3

He used the term subsistence to distinguish between the divine essence and his tri-personality. These sorts of considerations are sometimes developed under the heading ontological Trinity—that is, the Trinity regarding God’s being. He reminded us that there are certain attributes which belong to each Trinitarian person which are not shared among the persons of the Trinity. Recognizing these distinctions is part of not “confounding the persons” (Athanasian Creed). These properties unique to each person distinguish (not separate) each person from the others. For example, only the Father is unbegotten. “The Father is made of none, neither created, nor begotten” (Athanasian Creed). The Son, because he is such, is eternally begotten. “The Son is of the Father alone, not made, nor created, but begotten” (Athanasian Creed). Only the Spirit is able to proceed from the Father and the Son. “The Holy Ghost is of the Father and Son, neither made, nor created, nor begotten, but proceeding” (Athanasian Creed). Considered distinctly, however, each divine person can be said to be God “of himself,” that is, the Father, Son, and Spirit subsist of themselves. “And in this Trinity none is afore, or after other; none is greater, or less than another” (Athanasian Creed).

At the same time, Calvin also reminds us of another heading in the doctrine of the Trinity, the economic Trinity. This relates to the outworking of creation and redemption. For example, it belongs to the Son to become incarnate. It belongs to the Father to elect people to faith in Christ. It belongs to the Spirit to draw sinners to Christ and to sanctify them through the Word. Under this heading, we can think of the Father primarily as the Creator. The first articles of the Nicene and Apostles’ Creeds both encourage this sort of thinking. The Son can be said to have voluntarily subordinated himself to the Father, for the sake of redeeming his people, and the Spirit voluntarily subordinates himself to the Father and the Son for the sake of sanctifying his people, as the Nicene and Apostles’ Creeds both teach.

Thinking in these categories does not imply, however, that either the Son or the Spirit became less than they were; otherwise we would be “dividing the persons” (Athanasian Creed). Rather, these distinctions are a part of the administration of salvation, not changes in the divine being.

Both the personal distinctions within the Trinity and the Trinitarian character of God’s works of creation and redemption witness to the fundamental unity in the divine being. They also witness to the eternal fellowship and love which exists within the Trinity. The Greek Fathers spoke of God’s perichoresis, or what Francis Turretin called the “mutual intertwining” of the persons of the Deity.4 In this case, we know that the Trinity we worship is no static deity, but rather that there are dynamic relations among the Father, the Son, and the Spirit. It is out of that dynamic, loving fellowship that both creation and redemption have issued.

Conclusion

The doctrine of the Trinity is of the essence of our religion. We cannot and should not think of creation or redemption as anything but Trinitarian operations. This is a duty of the Christian faith. Christianity is more than duty, however. Being drawn to greater wonder and awe before the face of God is one of his best gifts. The Trinity reminds one that the Christian religion is not about us, but about God and his glorious grace. The Father to whom we pray is the eternal Father of our Lord Jesus Christ, in whose name we pray, and the Spirit in whose power we pray is of the same substance as the Father and the Son, and he is their gift to us to draw us by Christ to the Father.

Since the Trinity is such a necessary mystery, though woefully misunderstood or forgotten in our churches, how can we recover this truth? Three sources have helped me. First, God’s Word is thoroughly Trinitarian, and it is the fundamental source of all Christian teaching. Second, it was through meditating on the Nicene and Athanasian Creeds that I began to read Scripture with renewed Trinitarian eyes. Third, the Athanasian and Nicene Creeds also alerted me to the fact that Reformed theology is unreservedly Trinitarian.5 It structures our theology. Calvin’s Institutes (1559) were laid out along the lines of the Creed. The Heidelberg Catechism (1563) is in three parts, each roughly corresponding to the work of the economic Trinity.

The benefits of reading the Bible in the communion of the saints (e.g., Athanasius, Basil, Calvin) have been revolutionary. Recovering the doctrine of the Trinity has delivered me from a warped conception of God. I have learned again that there is no other God than the God who is one substance in three subsistences (persons); that the Christian is not entitled to think of God in any other way than he has revealed himself (Heidelberg Catechism 25, 96); that with Calvin and before him Gregory of Nazianzus (330-89) we must say, “I cannot think on the one without quickly being encircled by the splendor of the three; nor can I discern the three without being straightaway carried back to the one.”6 For Gregory, for Calvin, and for us, to think of God as triune is not a second blessing, reserved for the illuminati. Rather, it is how anyone must think of God, for any other god is an idol to be rejected.7

Notes

  1. The great Reformed theologian Francis Turretin spoke of the “adorable mystery” of the Trinity. See Francis Turretin, Institutes of Elenctic Theology, 3 vol., trans. G. M. Giger, ed. J. T. Dennison, Jr. (P&R Publishing, 1992–1997), 1:3:23.
  2. See Calvin, Institutes, 1.13. Also see B. B. Warfield, “Calvin’s Doctrine of the Trinity,” The Princeton Theological Review 7 (1909), 553–652, reprint in Calvin and Calvinism (New York, 1931). The latter edition is used here. See also R. Scott Clark, “The Catholic-Calvinist Trinitarianism of Caspar Olevian (1536-87),” Westminster Theological Journal 61 (1999): 15–39.
  3. Calvin, Institutes, 1.13.2, 6.
  4. Turretin, Institutes, 1:3:23:13.
  5. On this point, see R. Scott Clark, “The Catholic-Calvinist Trinitarianism”; Carl R. Trueman, The Claims of Truth: John Owen’s Trinitarian Theology (Paternoster, 1998); Carl R. Trueman and R. Scott Clark, ed., Protestant Scholasticism: Essays in Reassessment (Paternoster, 1999).
  6. “On Holy Baptism,” oration 40.41, cited in Calvin, Institutes, 1.13.17.
  7. Witsius, Hermann Witsius, The Apostles’ Creed, 1:129, 135.

©R. Scott Clark. All Rights Reserved.

Editor’s Note: This was originally published in a 1999 edition of Modern Reformation Magazine, and on the Heidelblog in 2012.

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  • R. Scott Clark
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    R.Scott Clark is the President of the Heidelberg Reformation Association, the author and editor of, and contributor to several books and the author of many articles. He has taught church history and historical theology since 1997 at Westminster Seminary California. He has also taught at Wheaton College, Reformed Theological Seminary, and Concordia University. He has hosted the Heidelblog since 2007.

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