What is the Trinity?

What the Bible says

The word "Trinity" does not appear in the Bible. But what the word protects is found throughout it. The starting point is the Old Testament's most basic confession.

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

Deut 6:4

God is one. Isaiah says the same: "there is no God but Me" (Isa 45:5). The New Testament never withdraws this confession. Yet in speaking of this one God it keeps setting three names side by side. After his resurrection Jesus commands his disciples.

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,

Matt 28:19

Notice that "name" is singular. Father, Son and Spirit stand together in one name. Paul's letter to Corinth ends with the same three.

The grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit be with all of you.

2 Cor 13:14

At Jesus' baptism too all three appear together. The Spirit descends like a dove, and a voice from heaven says, "This is My beloved Son, in whom I am well pleased" (Matt 3:16-17).

Who, then, is the Son? John says it in his opening lines.

In the beginning was the Word, and the Word was with God, and the Word was God.

John 1:1

The Word was "with God," so he is distinct from the Father, and the Word "was God," so he is God. This Word became flesh and lived among us (John 1:14), and Thomas confessed to the risen Jesus, "My Lord and my God!" (John 20:28).

And the Spirit? He is presented not as a force or an influence but as a person. Before leaving, Jesus says:

And I will ask the Father, and He will give you another Advocate to be with you forever

John 14:16

"Another" Advocate means one who helps just as Jesus himself has helped. Peter also tells Ananias that he has "lied to the Holy Spirit," and then says, "You have not lied to men, but to God!" (Acts 5:3-4). To lie to the Spirit is to lie to God.

Scripture also shows these three in a love that has always been. Jesus prays to the Father about "the glory You gave Me because You loved Me before the foundation of the world" (John 17:24). Before creation, when there was no one else, there was already love.

The church's witness

The church had to gather these testimonies into a single confession. From very early on Christians baptized in the name of the Father, Son and Spirit, and worshipped Christ alongside the Father. In the fourth century, though, when Arius taught that the Son was a created being, a great dispute broke out. The Council of Nicaea (325) declared the Son to be of one substance with the Father, and the Council of Constantinople (381) added the confession about the Spirit, giving us the Nicene Creed as we have it The Nicene Creed.

One thing should be said plainly. The Western church added to the creed that the Spirit proceeds "from the Father and the Son," while the Eastern church kept the original wording, "from the Father." The West meant to honour the Son's full equality with the Father; the East holds that the Father alone is the source within God, and objects to changing a shared creed without a shared council. The difference remains, though both confess the same one God in three persons.

On Matthew 28:19 Jerome writes that the words "In the name of the Father, the Son, and the Holy Ghost" are used "that they whose Godhead is one should be conferred at once, to name this Trinity, being to name One God" Jerome. On John 1:1 Theophylact says, "Sabellius is overthrown by this text." Sabellius held that Father, Son and Spirit are one person who sometimes appears as one, sometimes as another, but the text says that the Word was "with" God Theophylact.

Hilary, on John 14:9, says that the Lord’s words do not point to "one person solitary and without relationship" Hilary. Matthew Henry, on Deuteronomy 6:4, reads the "three-fold mention of the Divine names" as seeming "plainly to intimate a Trinity of persons, even in this express declaration of the unity of the Godhead" Matthew Henry. Many theologians doubt that the Old Testament teaches the Trinity this clearly; they speak rather of hints that come into view only in the light of the New Testament.

In the original languages

The "One" of Deuteronomy 6:4 is the Hebrew echad (אֶחָד). It is the ordinary word for "one," so it cannot carry the doctrine by itself. But it can also describe a unity of more than one: in Genesis 2:24 man and woman become "one" flesh. So the wording of "the LORD is One" need not exclude richness within God.

The "Word" of John 1:1 is logos (λόγος), which also carries the senses of "reason" and "account." John uses it to introduce one who is with God and is God. For some Greek philosophers the logos was the ordering principle of the world; in the Jewish Scriptures God creates by his word. John says that this Word became a human being.

Common objections

"It is not in the Bible." This is a fair observation. The word "Trinity" is not in Scripture. It first appears in Greek in Theophilus of Antioch (late second century) and in Latin in Tertullian (early third), and "substance" in the Nicene Creed is not a biblical word either. So some readers conclude that the doctrine was invented later, and some groups do not accept it. The church's answer is that the word came later but the content is in the Bible. Confessing one God while speaking of Father, Son and Spirit in ways that belong to God alone is a pattern across the New Testament. Because there were many ways of misreading this testimony, the church needed new words to rule out the wrong readings. A new word is not the same as a new idea. Whether that judgement holds depends on how one reads Scripture, so readers are encouraged to examine the passages for themselves.

"It is illogical. Does it not say that one is three?" This objection is strong. If the church said "God is one and also three" in the same sense, it would be a contradiction. But the church does not say that. It says that God is one in being and three in persons. It does not say one and three in the same respect. The doctrine is not three gods (tritheism), and it is not one person appearing in three roles (modalism). The church rejected both. None of this makes the doctrine easy. Analogies such as water, the sun, or a three-leaf clover all break down somewhere, and the Fathers knew it. If God were someone we could fully grasp, he would be no larger than we are. What goes beyond understanding is not the same as what contradicts itself.

Going further

The Trinity is not an exam question for theologians but a confession about God's love. If God had been from the beginning a single solitary person, there would have been no one to love before creation. Yet Scripture says the Father loved the Son before the foundation of the world. So God is not only one who loves but one who is love (1 John 4:8). Matthew Henry, on 2 Corinthians 13, sums up this grace: all the benefits which Christ of his free grace has purchased, the Father out of his free love has purposed, "and the Holy Ghost applies and bestows" Matthew Henry.

You might ask yourself some questions. Have I thought of God as one power or one being, or have I ever thought of him as the relationship of Father, Son and Spirit? What does it mean to me that God has been love from before time?

To read further, see Is Jesus God? and Who is the Holy Spirit?