TheologyScriptureHistorical
What is the Trinity?
Is it biblical? Is there more than one God? Is it a logical contradiction?
Last updated: 09/08/2025
TL;DR

Understanding the Trinity


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].



Biblical Foundation


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]



Key Theological Terminology


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].



  • Ousia (Essence/Substance): Refers to *what* God is—His single, undivided divine nature, substance, and attributes (e.g., omnipotence, omnipresence). The three persons share this one *Ousia* completely[27].

  • Hypostasis (Person): Refers to *who* God is—the three distinct, concrete realities (Father, Son, and Holy Spirit) that subsist in the one divine essence. This distinction is based on their unique, eternal relationships of origin[28].

  • Homoousios: The key term adopted at the Council of Nicaea, meaning "of the same essence" or "consubstantial." It affirms that the Son is fully God, sharing the exact same divine substance as the Father, and is not merely a similar substance (*homoiousios*)[29].



Common Objections Answered



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].



Historical Development and Heresies


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].



  • Arianism: Condemned at Nicaea, Arianism claimed the Son was a created being, subordinate to and not co-eternal with the Father (*homoiousios* or "like essence" rather than *homoousios*)[44].

  • Modalism: Condemned indirectly, Modalism (or Sabellianism) asserts God is a single person who manifests Himself in three successive modes, denying the simultaneous, distinct personhood of Father, Son, and Holy Spirit[45].

  • The Nicene Creed: The resulting Nicene-Constantinopolitan Creed is the universally accepted orthodox formulation that definitively states the Father, Son, and Holy Spirit are one God in three co-equal and co-eternal persons[46].



Practical Implications


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].


Key Bible Verses
Deuteronomy 6:4
Isaiah 45:21
John 1:1
John 20:28
Acts 5:3-4
Matthew 3:16-17
John 15:26
Philippians 2:6-8
2 Corinthians 13:14
Sources & Further Reading