One God in three persons

This week's questions

Are there more Gods than one? There is but one only, the living and true God.

Question 5

How many persons are there in the Godhead? 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.

Question 6

Question 4 said what God is (last week); Question 5 says that there is only one such God, and Question 6 that in the one God there are three persons. This is not a Presbyterian or Reformed peculiarity but the faith of the Trinity, which the Orthodox, the Catholic Church and the Protestant churches confess together.

One only, the living and true God

The first proof text of Question 5 is Israel's daily confession, the Shema:

Hear, O Israel: The LORD our God, the LORD is One.

Deuteronomy 6:4

That God is one does not mean a council of gods, or a high god ruling lesser ones. Writing to Corinth, a city of many so-called gods and lords, Paul says, "We know that an idol is nothing at all in the world, and that there is no God but one" (1 Corinthians 8:4). The next proof text is Jeremiah's cry beside idols cut from the forest and decked with silver and gold, which cannot speak or walk: "But the LORD is the true God; He is the living God and eternal King" (Jeremiah 10:10). The living God speaks and acts, as no made god can; the true God is no vanity, and there is no other.

Three persons, one God

The second proof text of Question 6 is the risen Lord's commission:

Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit

Matthew 28:19

The three are named side by side, and baptism is in their one name. The first proof text is 1 John 5:7. The divines cited it as the Bibles of their day read it, and the King James Version still reads there of ‘three that bear record in heaven, the Father, the Word, and the Holy Ghost’. Most Greek manuscripts lack these words, and the BSB, like most modern versions, does not have them (1 John 5:6-8); some Christians hold the longer reading to be genuine. Either way, the doctrine never rested on that verse. The Larger Catechism also cites the Spirit descending and the Father's voice at Jesus' baptism (Matthew 3:16-17), Paul's blessing (2 Corinthians 13:14) and Jesus' words about himself and the Father (John 10:30) Larger Catechism, Q. 9, and it answers that Scripture ascribes to the Son and the Spirit "such names, attributes, works, and worship, as are proper to God only" Q. 11. The Word "was God" (John 1:1), and Ananias, lying to the Holy Spirit, had "not lied to men, but to God" (Acts 5:4).

‘Person’ and ‘substance’ are words the church refined to guard this confession. Substance says what God is; person says who. God is one in substance and three in persons, really distinct. ‘The same in substance’ carries forward the homoousios the Council of Nicaea confessed of the Son in 325, "of one substance with the Father" Nicene Creed. ‘Equal in power and glory’ means that the Son and the Spirit are not lesser gods; in the Athanasian Creed's words, "none is greater, or less than another" Athanasian Creed. The story that Patrick taught the Trinity with a shamrock is a much later legend, and such pictures fail: they divide God into three pieces, or make one person change into three appearances.

The Nicene Creed is confessed by the Orthodox, Catholics and Protestants together; the Athanasian Creed, which arose in the West, is received by the Catholic Church and many Protestant churches. The Belgic Confession of the continental Reformed churches proves the doctrine from Scripture's testimonies, among them the ‘us’ of Genesis 1 and Jesus' baptism in the Jordan, and declares, "we do willingly receive the three creeds" Belgic Confession, Art. 9. Their Heidelberg Catechism asks why, if there is but one divine being, we speak of three, and answers:

Because God has so revealed himself in his Word that these three distinct Persons are the one, true, eternal God.

Heidelberg Catechism, Q. 25

One difference remains between the churches. In the West the creed confesses the Spirit's procession from the Father ‘and the Son’ (the filioque); the Orthodox keep the words of 381, ‘from the Father’ The Nicene Creed. Outside the ecumenical faith, Oneness Pentecostals believe that God is one person, and that Father, Son and Spirit are names of the one God's revealing of himself, so they baptise in the name of Jesus (Acts 2:38); Unitarians confess the Father alone as God. The church has answered from Matthew 28:19, where three are named and distinguished within the one name. The Trinity, in the Christian Doctrine course, and Nicaea, in the Theology course, tell the history and the errors the church rejected; see also What is the Trinity?, Is Jesus God? and Who is the Holy Spirit?

To ponder this week

When you pray this week, do you know to whom you come, through whom, and by whom? Paul tells what Christ has opened for us: "For through Him we both have access to the Father by one Spirit" (Ephesians 2:18). We come to the Father through the Son, and by the one Spirit. Recall that order once as you begin to pray, and end in the Lord's name with Amen.

Practice