What is the Trinity?

The doctrine of the Trinity holds together two truths that run through the Bible. First, there is only one God: "Hear, O Israel: The LORD our God is one LORD" (Deuteronomy 6:4). Second, the Father, the Son, and the Holy Spirit are each presented as God. The Father is called God throughout Scripture. Of the Son, John writes, "In the beginning was the Word, and the Word was with God, and the Word was God" (John 1:1), and "the Word was made flesh, and dwelt among us" (John 1:14). The Holy Spirit is treated as a person and as God: when Ananias lied "to the Holy Ghost," Peter told him, "thou hast not lied unto men, but unto God" (Acts 5:3-4). All three appear together at Jesus' baptism, as the Son comes up from the water, the Spirit descends like a dove, and the Father speaks from heaven (Matthew 3:16-17). Jesus commanded baptism "in the name of the Father, and of the Son, and of the Holy Ghost" (Matthew 28:19), using the singular "name," and Paul's blessing in 2 Corinthians 13:14 names all three. The word "Trinity" first appears in Christian writings of the late second century, and the doctrine was formally defined at the councils of Nicaea (325) and Constantinople (381) in response to teachings that denied the full deity of Christ or of the Spirit. Christians stress that it does not mean three gods, nor one God taking on three roles at different times, but one God in three persons, equal and eternal. The KJV also includes 1 John 5:7, "the Father, the Word, and the Holy Ghost: and these three are one"; most textual scholars think that wording was a later addition, while some KJV readers defend it, but the doctrine rests on the wider witness of Scripture either way. The Trinity is confessed by Catholic, Orthodox, and Protestant churches alike.

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