Step 9 of 9 · The Christian confession
What is the Trinity?
In brief
Christians confess one God who exists eternally as Father, Son and Holy Spirit: not three gods, and not one person wearing three masks. The doctrine is the Church's way of holding together what the whole Bible teaches about the one God of Israel, the divine identity of Jesus, and the personal work of the Spirit.
The 2-minute version
The Trinity is not built on one disputed verse. It begins where Israel began, with the confession that the Lord is one (Deuteronomy 6:4). The New Testament never abandons that confession, yet it places Jesus within it, speaking of one God the Father and one Lord Jesus Christ, and it speaks of the Spirit as personal, sent by the Father and the Son. Early Christians baptized in the one name of the Father, the Son and the Holy Spirit, and prayed to Christ. Early in the third century Tertullian already speaks of the Unity distributed into a Trinity. The fourth-century councils used philosophical terms such as homoousios, “of the same substance”, to guard that faith against teachers who made the Son a creature, and the creed of 381 confessed the Spirit as Lord and Giver of Life. The word “Trinity” is later than the Bible; the pattern it names is not. It remains a mystery confessed, not a puzzle solved.
The strongest objection
The Trinity is not taught in the Bible: the word never appears, Jesus says “the Father is greater than I” and does not know the hour, and the doctrine was formulated in the fourth century with Greek philosophical terms under imperial pressure. It is a later development, not the faith of Jesus' Jewish followers.
A response
The word is later; the pattern is not. The New Testament writers assume Jewish monotheism and still speak of Jesus and the Spirit in ways that belong to God alone, and Christians were baptizing in the threefold name long before Nicaea.
Texts like “the Father is greater than I” (John 14:28) are addressed within the doctrine itself, which confesses that the Son truly became human. Nicaea used philosophical vocabulary to defend a confession, not to create one; the site's article on whether the Trinity was invented takes the history step by step.
Take the objection further: Is the Trinity Biblical, or Was It Invented Later?
The evidence
From Scripture
- Deuteronomy 6:4 — The one God of Israel.
- Matthew 3:13–17; 28:19 — Father, Son and Spirit at the baptism; the threefold name.
- John 1:1–14 — The Word who was God and became flesh.
- 1 Corinthians 8:6; 2 Corinthians 13:14 — One God the Father, one Lord Jesus Christ; the threefold blessing.
- John 14:26; 15:26 — The Spirit sent by the Father and the Son.
From history
- Before Nicaea. Tertullian, writing early in the third century.
“the mystery of the dispensation is still guarded, which distributes the Unity into a Trinity, placing in their order the three Persons — the Father, the Son, and the Holy Ghost”
- Nicaea (325). The original creed confesses the Son as of one substance with the Father and ends simply with the Holy Spirit.
“We believe in one God, the Father almighty, maker of all things visible and invisible”
- Constantinople (381). The fuller creed confesses the Spirit as Lord and Giver of Life, who proceeds from the Father.
- The filioque. The words “and the Son” were added to the creed in the West later; Orthodox and Catholic sources agree they were not in the text of 381.
Primary sources
5 sources for this step
- , Chapter 7 — Early baptismal formula (ANF, via New Advent).
- , Against Praxeas 2 — Translated by Peter Holmes (ANF), via New Advent.
“the mystery of the dispensation is still guarded, which distributes the Unity into a Trinity, placing in their order the three Persons — the Father, the Son, and the Holy Ghost”
- , The Creed of Nicaea — Greek, Latin and English, via Early Church Texts.
“We believe in one God, the Father almighty, maker of all things visible and invisible”
- , The Symbol of Faith: the Nicene Creed — The Nicene-Constantinopolitan Creed as the Orthodox Church confesses it.
- , “Filioque” — A Catholic reference on the history of the addition.
Read the full case
The Biblical Case for the Trinity
- Infographic The Trinity: A Biblical, Historical, and Orthodox Christian Defense
- Answered question Is the Trinity logical or incoherent?
- Explainer deck What Is the Trinity?
- Interactive guide Doctrine Over Time