Essence

What God is

When the church confesses the Trinity, it says that God is one in essence and three in persons. Person answers the question who; essence answers what. The Father, the Son and the Spirit share one and the same divine essence, so that the three together are one God. Three human beings share a common human nature and are still three people, but the divine essence cannot be divided or counted like that.

Scripture reveals God's being through his name:

God said to Moses, “I AM WHO I AM. This is what you are to say to the Israelites: ‘I AM has sent me to you.’”

Exodus 3:14

God receives his existence from no one; he simply is. "God is Spirit," Jesus said (John 4:24). And Paul writes of Christ, "For in Christ all the fullness of the Deity dwells in bodily form" (Colossians 2:9). The word for Deity, theotēs (θεότης), means the very being of God: not a share of it, but all of it, is in the Son.

Yet we cannot comprehend God's essence. He "dwells in unapproachable light" (1 Timothy 6:16). We know him truly, as far as he makes himself known, but never exhaustively. What Scripture tells us of God's holiness, love, power and wisdom the church calls the attributes of God. They are not parts added to his essence but different ways of describing the one undivided God as he has made himself known. The church has called this God's simplicity.

The church's word

The Greek word is ousia; Latin used substantia or essentia. The Council of Nicaea in 325 confessed that the Son was begotten of the essence of the Father and is of one being with him. The Cappadocian Fathers then fixed the distinction between ousia, essence, and hypostasis, person. Augustine judged essentia a better word for God than substantia, which suggested something underlying changeable qualities Augustine, On the Trinity. The Belgic Confession of 1561 says:

we believe in one only God, who is one single essence, in which are three persons, really, truly, and eternally distinct, according to their incommunicable properties; namely, the Father, and the Son, and the Holy Ghost.

Belgic Confession, art. 8

Where the traditions differ

All the main traditions confess that God's essence is one and beyond any creature's grasp. They explain differently how we come to know God and share in his life. The Orthodox churches follow Gregory Palamas (fourteenth century): God's essence can never be known or shared by creatures, yet God truly gives himself in his uncreated energies, his own activity and grace. So they read the promise that we may "become partakers of the divine nature" (2 Peter 1:4) as participation in God's energies, not in his essence.

The Catholic Church, following Thomas Aquinas, teaches that in God essence and existence are one, and that the blessed in heaven will see God's essence, though without comprehending it Thomas Aquinas, Summa Theologiae. The Reformation confessions kept the older teaching that God is a simple being, while finding the way to know him in the revelation of Scripture and above all in Christ. Each tradition, in its own way, means to guard both God's majesty and the reality of his self-giving. See the lesson What God is like.