Why does the church refer to the Holy Spirit as “third person?”

The Holy Spirit is coequal with God the Father and God the Son in both essence and person-ness. The Father is the source of the divine essence and a person, the eternally begotten Son is the image of the divine essence and a person, and the Holy Spirit proceeds from the Father’s divine essence and is a person. The Holy Spirit is counted as third, then, not because he is of a lesser rank or different substance than the other two persons of the holy Trinity; nor is he third because he is not a person, for he is a person indeed. Nor do we use numbers in reference to the persons of the Trinity because they are fully adequate descriptors.

Rather, the Holy Spirit is the third person of the Trinity because he proceeds from the Father through the Son. In other words, his sending and receiving is mediated through the Son. Thomas Torrance writes:

Our receiving of the Spirit is objectively grounded in and derives from Christ who as the incarnate Son was anointed by the Spirit in his humanity and endowed with the Spirit without measure, not for his own sake (for he was eternally one in being with the Spirit in God) but for our sakes, and who then mediates the Spirit to us through himself. (Thomas F. Torrance, The Christian Doctrine of God: One Being Three Persons, The Cornerstone Series [New York: T&T Clark, 1996], 148.)

When the Father sends the Spirit into the world, it is through the Son and on the basis of the Son’s redemptive work. The incarnation is for the sake of Pentecost and the latter is dependent upon the former. It is through union with Christ that the church receives the Spirit. The Holy Spirit is “third” because God the Father “gives” God the Son to the world, after which he sends the Holy Spirit through the Son and with the Son.

It should be noted that this way of thinking about the Holy Spirit as the third person of the Trinity is focused on the Holy Spirit in his function pertaining to the Trinity’s relationship with the creation (the economic Trinity, or God ad extra). There is debate within the church as the notion of thirdness regarding the Holy Spirit within the inner life of the holy Trinity (the immanent Trinity, or God ad intra). The details of that debate are far beyond the scope of this book.

Eternal Processions—from the Father Through the Son

The Nicene-Constantinopolitan Creed is very intentional in its language that the Holy Spirit proceeds from the Father and the Son. What does this mean? Gregg Allison answers that question concisely with this: “This [procession] does not mean that the Holy Spirit was created by them, or that his divine nature is derived from theirs, or that he is inferior, but it means that he is eternally dependent on them for his person-of-the-Spirit.” (Gregg R. Allison, “Eternal Processions” in The Baker Compact Dictionary of Theological Terms [Grand Rapids: Baker Books, 2016]). We mentioned that the concept of personhood (hypostasis) means “subsisting relations,” meaning that a person is only a person as they are in relationship with other persons. The distinctness of the Holy Spirit within the Godhead is derived from his relationship with the Father and the Son. The distinctness of the Son from the Father and the Spirit is marked by the phrase “eternally begotten.” Similarly, the distinctness of the Spirit is marked by the phrase “eternally proceeds.” But what does it mean to proceed? In the simplest sense, “proceeds” simply means “sent.” Beyond this, we must hit the mystery button. Gregory of Nazianzus writes:

What then is Procession? Do you tell me what is the Unbegottenness of the Father, and I will explain to you the physiology of the Generation of the Son and the Procession of the Spirit, and we shall both of us be frenzy-stricken for prying into the mystery of God. And who are we to do these things, we who cannot even see what lies at our feet, or number the sand of the sea, or the drops of rain, or the days of Eternity, much less enter into the Depths of God, and supply an account of that Nature which is so unspeakable and transcending all words? (Gregory of Nazianzen, Oration 31, NPNF2 7:320.)

The Old Testament witnesses to God’s unicity. The New Testament affirms the witness of the oneness of God while further witnessing that Jesus and the Holy Spirit are also divine. In response to the rise of heretical teaching that Jesus and the Holy Spirit were either lesser deities (homoiousion) or not divine (heteroousion), the church definitively and unanimously affirmed the oneness of God with the distinction of three persons: the Father, the Son, and the Holy Spirit; the holy Trinity. The Trinitarian concept of “unity with distinction” is captured in the terms homoousion (“same substance”), hypostasis (“person”), and perichoresis (“mutual indwelling”). Within the Trinity, the Holy Spirit is the third person of the Trinity who eternally proceeds from the Father through the Son.

Why It Matters

Why does it matter that God is three persons and that the Holy Spirit eternally proceeds from the Father through the Son? It matters because we are made in the image of God. This means that the triune life of God is the model after which human life, fulfillment, purpose, and our very existence is based. If we don’t understand that God is three persons, we will never understand what human life is all about. More specifically, because God is three persons, we can understand that to be human is to be in self-giving love relationship with others. We are made not for ourselves but one another. Just as each member of the Trinity exists for the other, so it is with human life. As persons, we will find that the most important thing about us is our relationships with others. It is not our gender, race, nationality, or unique personalities. The most important thing about us, what makes you you, is relationships. We don’t have relationships; we are relationships. Ultimately, it is our relationship with the Trinity that defines us.

—

If you would like to learn more about the Holy Spirit, Matt Ayars’s new book The Holy Spirit: An Introduction. This readable systematic theology works through the person and work of the Spirit that offers a comprehensive overview not just of this doctrine but as a vision for the Spirit’s indispensable role in the victorious Christian life.

Readers will come away with the sound biblical and historic Christian basis for the divine personhood of the Holy Spirit and the optimism of living a Christian life that is free from the power of sin. This results from the graceful reality of the indwelling Spirit, who unites our lives with Christ. This book—The Holy Spirit: An Introduction—drives home our high privilege of having the Holy Spirit restore the image of God in individuals by uniting us to Jesus. It will serve as an indispensable resource for leaders, students, and anyone desiring to deepen their understanding of the Holy Spirit.

WATCH THE FREE TEACHING VIDEOS