The Word "Trinity" Isn't in the Bible
Did you know the word "Trinity" appears nowhere in the Bible? The specific term was coined by the North African theologian Tertullian around AD 200 as Latin Trinitas. The WORD is post-biblical. But the DOCTRINE — one God existing as three co-eternal Persons — is everywhere in Scripture.
Yes, the word is absent from the text.
Search all 66 books, Hebrew Old Testament and Greek New Testament. The word Trinity (or its Hebrew and Greek equivalents) does not appear. Anti-Trinitarian groups (Jehovah's Witnesses, Mormons, Oneness Pentecostals, various Unitarians) regularly cite this fact as their argument against the doctrine.
The response of the historic Christian church has been: the absence of the WORD does not mean the absence of the DOCTRINE.
Tertullian and the Coinage:
Tertullian of Carthage (~155-220 AD) was the first major Christian theologian to write extensively in Latin. In his treatise Against Praxeas (~AD 213), he coined the Latin term Trinitas ("threeness") to describe the one God existing as three Persons. He also introduced the theological usage of persona (person) to describe the Father, Son, and Spirit.
Tertullian's shorthand was later formalized in:
— The Nicene Creed (AD 325) — affirmed the deity of the Son against Arius
— The Constantinople Creed (AD 381) — added the deity of the Spirit
— The Athanasian Creed (~5th century) — the most detailed early Trinitarian confession
The Biblical Case — the Doctrine Is Everywhere:
Genesis 1:26 — "Let US make man in OUR image." Reformed exegesis treats the plural as an intra-Trinitarian conversation.
Deuteronomy 6:4 (the Shema) — the Hebrew word for "one" (echad) describes UNIFIED or COMPOUND unity (as in Gen 2:24, husband and wife becoming echad — one flesh), not absolutely solitary singularity (yachid).
Matthew 3:16-17 — Jesus's baptism. All three Persons appear simultaneously.
Matthew 28:19 — the Greek grammar is decisive: one NAME (eis to onoma, singular), three Persons.
John 1:1-3 — "the Word was God."
2 Corinthians 13:14 — Paul's Trinitarian benediction.
1 Peter 1:2 — "elect according to the foreknowledge of God the Father, in the sanctification of the Spirit, for obedience to Jesus Christ."
The Historic Christian Confession:
Athanasian Creed: "We worship one God in Trinity, and Trinity in unity, neither confounding the Persons nor dividing the substance."
Westminster Confession 2.3: "In the unity of the Godhead there be three Persons of one substance, power, and eternity: God the Father, God the Son, and God the Holy Ghost. The Father is of none, neither begotten, nor proceeding; the Son is eternally begotten of the Father; the Holy Ghost eternally proceeding from the Father and the Son."
Calvin (Institutes I.13): an entire book devoted to defending the Trinity from Scripture. Calvin's argument is decisive: the doctrine is thoroughly biblical whether or not the specific Latin word appears in the text.
Herman Bavinck (Reformed Dogmatics II): "The doctrine of the Trinity is not a philosophical construction imposed on Scripture; it is the church's careful confession of what Scripture reveals about the one God in three Persons. The word is post-biblical; the reality is biblical throughout."
Other Words That Aren't in the Bible (but the Doctrine Is):
"Bible" (Greek biblia), "monotheism" (17th c.), "incarnation," "hypostatic union," "ecclesiology," "eschatology," "atonement." All post-biblical shorthand for biblical realities. The absence of a technical term does not mean the absence of the concept.
The Pastoral Implication:
If someone tells you the Trinity isn't biblical because the word isn't in the Bible, they've made a category error. Words are the church's ministerial shorthand for realities Scripture reveals. The doctrine of the Trinity is the church's confession of the one God who reveals Himself throughout Scripture as Father, Son, and Holy Spirit — one being, three Persons.
Tertullian gave us the word. Scripture gave us the doctrine.
The Trinity is biblical. The word is just newer than the text.
📖 Passages: Genesis 1:26, 3:22, 11:7, Deuteronomy 6:4, Isaiah 6:8, Matthew 3:13-17, 28:19-20, Luke 1:35, John 1:1-3, 14:16-17, 26, 15:26, 16:7, 2 Corinthians 13:14, Ephesians 4:4-6, Titus 3:4-6, 1 Peter 1:2, 1 John 5:6-11