The Trinity is the Christian doctrine that God exists as three distinct persons - Father, Son, and Holy Spirit - while remaining one God in essence[1]. This is not three Gods (tritheism) nor one person in three modes (modalism), but one divine Being existing eternally in three persons who share the same divine nature[2][3]. The doctrine is a mystery revealed by God, emphasizing that the oneness refers to His essence (*what* He is), and the threeness refers to the persons (*who* He is)[4].
While the word "Trinity" isn't in Scripture, the concept is clearly taught throughout the Bible[5], derived from the totality of the biblical data[6]:
One God: The Bible consistently affirms monotheism[7]
• "Hear, O Israel: The Lord our God, the Lord is one" (Deuteronomy 6:4)[8]
• "There is no God apart from me" (Isaiah 45:21)[9]
The Father is God: Clear biblical teaching[10]
• "Grace and peace to you from God our Father" (1 Corinthians 1:3)[11]
• Jesus prays to "our Father in heaven" (Matthew 6:9)[12]
Jesus is God: Scripture explicitly identifies Jesus as divine[13]
• "In the beginning was the Word, and the Word was with God, and the Word was God" (John 1:1)[14]
• "My Lord and my God!" Thomas declares to Jesus (John 20:28)[15]
• Jesus claims divine names and prerogatives (John 8:58, Mark 2:5-7)[16]
The Holy Spirit is God: Biblical evidence for the Spirit's divinity[17]
• Lying to the Holy Spirit is lying to God (Acts 5:3-4)[18]
• The Spirit has divine attributes: omniscience (1 Corinthians 2:10-11), omnipresence (Psalm 139:7-10)[19]
• The Spirit performs divine works: creation (Genesis 1:2)[20], resurrection (Romans 8:11)[21]
Three Distinct Persons: Scripture shows the persons relating to each other[22]
• Jesus' baptism: Father speaks, Son is baptized, Spirit descends (Matthew 3:16-17)[23]
• Jesus prays to the Father (John 17:1-5)[24]
• Jesus promises to send the Spirit from the Father (John 15:26)[25]
To guard against heresy, the early church used Greek terms to articulate the biblical data. The formula is often summarized as One Ousia, Three Hypostases[26].
Objection: "Trinity is a logical contradiction"
Response: The Trinity is not 1+1+1=1, but rather one What (divine essence) in three Whos (persons)[30]. It is not contradictory because the claim of unity and threeness are not made in the same sense[31]. The Trinity is a mystery (beyond full human understanding) but not a contradiction (a logical impossibility)[32].
Objection: "The word 'Trinity' isn't in the Bible"
Response: Neither is "incarnation" or "omniscience," but these biblical concepts require theological terms[33]. The Trinity is derived from the necessity of summarizing all biblical data, not imposed upon it[34].
Objection: "Jesus said the Father is greater than I"
Response: This refers to Jesus' role in the incarnation, not His essence[35]. Jesus voluntarily took on human nature and a subordinate role for our salvation while remaining equal in divine nature (Philippians 2:6-8)[36].
Objection: "Early Christians didn't believe in the Trinity"
Response: Early church writings show Trinitarian thinking from the apostolic period[37]. The *Didache* (c. 60-120 AD) and the writings of Clement of Rome (c. 96 AD) refer to Father, Son, and Spirit in divine terms, indicating an "incipient Trinitarianism"[38]. The *Didache* explicitly instructs baptism in the triadic formula[39], and Clement invokes the Father, Son, and Holy Spirit together[40].
The Trinity was formally articulated at the Council of Nicaea (325 AD)[41] and completed at the First Council of Constantinople (381 AD)[42]. These councils didn't invent the doctrine but clarified biblical teaching against false interpretations (heresies)[43].
The Trinity explains God's relational nature (love existing eternally within the Godhead) and is central to the Christian understanding of salvation[47]. The Father plans salvation, the Son accomplishes it, and the Spirit applies it to believers (2 Corinthians 13:14)[48].