Person (hypostasis)

Who, not what

When the church confesses the Trinity, it says that God is one in essence and three in persons. Essence answers the question what God is; person answers who. The Father, the Son and the Spirit are not three parts of God, each a third of the whole. Each person has the whole divine being and is fully God.

Scripture shows the three facing one another. The Son prays to the Father; the Father loves the Son; the Son asks, and the Father gives "another Advocate" (John 14:16). These relations did not begin when the world did:

And now, Father, glorify Me in Your presence with the glory I had with You before the world existed.

John 17:5

What, then, distinguishes the persons? Not power, glory or holiness, which they share equally, but their relations to one another: the Father is from no one, the Son is eternally begotten of the Father, and the Spirit eternally proceeds. The Westminster Shorter Catechism sums it up:

There are three persons in the Godhead; the Father, the Son, and the Holy Ghost; and these three are one God, the same in substance, equal in power and glory.

Westminster Shorter Catechism, Q. 6

How the word was shaped

The Greek hupostasis (ὑπόστασις) meant something like ‘underlying reality’ or ‘confidence’ in the New Testament. Hebrews calls the Son "the exact representation of His nature" (Hebrews 1:3), and ‘nature’ there translates hypostasis. The word did not begin with the meaning ‘person’; the church shaped it in order to speak rightly of God.

Early in the third century Tertullian used the Latin persona, calling Father, Son and Spirit three persons of one substance Tertullian, Against Praxeas. The nearest Greek word, prosopon, could also mean a face or a role on stage, and so could sound like modalism, one God wearing three masks. In the fourth century the Cappadocian Fathers separated ousia and hypostasis, which had been used almost as synonyms: God is one ousia in three hypostases. Augustine admitted that ‘three persons’ does not capture God; we say it, he wrote, not to explain the mystery but so as not to be left silent Augustine, On the Trinity.

The same word serves when the church confesses Christ. The Council of Chalcedon in 451 taught that his two natures, divine and human, come together "in one Person and one Subsistence, not parted or divided into two persons" Definition of Chalcedon; ‘subsistence’ there translates hypostasis. The eternal Son, one person, took a human nature to himself: this is the hypostatic union.

A word that needs care

In modern speech a ‘person’ is often an independent individual who thinks and decides on his own, and three such individuals would be three gods. The church has never meant that. In the twentieth century Karl Barth preferred, for this reason, to speak of God's three ‘modes of being’ Karl Barth, Church Dogmatics; his critics replied that the phrase can sound like modalism. Other theologians lay great weight on the love and communion of the three persons, and their critics warn against picturing three gods. Both sides confess the same faith: one God, and the Father, the Son and the Spirit truly distinct persons. See the lesson The Trinity.