What is non-Trinitarian Christianity?

Trinitarianism is the teaching that God exists in three eternal, co-equal Persons who share one substance: Father, Son, and Holy Spirit. Non-Trinitarian Christianity denies one or more aspects of the triunity of God while still proclaiming Jesus Christ as the object of faith and worship.

Historic Christianity is Trinitarian. Since its beginning, the church has recognized that God has revealed Himself to be a triunity of three Persons. The doctrine of the Trinity was hinted at in the Old Testament and fully revealed in the New. At Jesus’ baptism, the triune God is quite evident:

In the span of two verses, we read of the voice from heaven (God the Father), Jesus (God the Son), and the dove (God the Holy Spirit). Many other passages of Scripture feature the three divine Persons as distinct yet equal. See Isaiah 48:16; 61:1; Matthew 28:19; Romans 15:16; 1 Corinthians 12:4–6; 2 Corinthians 13:14; Ephesians 4:4–6; and 2 Thessalonians 2:13.

Non-Trinitarianism takes different forms:

• Adoptionism (or Dynamic Monarchianism): Jesus was a mere human who was “adopted” as the Son of God at some point during His earthly life.
  
  
• Modalism (or Modalistic Monarchianism or Sabellianism): God is an indivisible being who manifests Himself as one of three Persons at various times. So, the Father, Son and Spirit are all the same person playing different roles.
  
  
• Unitarianism: God is a single, unified Person. The Son and the Spirit are not God.
  
  
• Subordinationism: The Son and Holy Spirit are of a lower rank than the Father, subordinate to Him in both nature and being.
  
  
• Patripassianism: God the Father suffered and died on the cross along with God the Son, or, more properly, the Father suffered as the Son—there being no real distinction between the Father and the Son.
  
  

Various religious groups who deny (or redefine) the Trinity include Unitarian Universalists, the Jehovah’s Witnesses, the Church of Jesus Christ of Latter-day Saints (Mormonism), Christian Science, traditional Armstrongism, Swedenborgianism, Christadelphianism, and the Jesus Only movement (Oneness Pentecostalism). Some of these groups may use Trinitarian language but attach different meanings to the terms they use. For example, Mormonism professes belief in the Father, Son, and Holy Spirit, but it denies the eternal nature of the Son, teaching that Jesus is a created being.

Non-Trinitarian Christianity is not true Christianity. We must worship God as He presents Himself in Scripture, not as we redefine Him.

The concept of the triunity of God appears throughout Scripture. It is not a concept readily grasped by our finite minds, but that is no reason to reject it. The doctrine of the Trinity is to be accepted by faith. Trying to explain away the true nature of God by denying the Trinity does violence to the biblical text. God’s nature is not subject to our limitations. He is who He is: one eternal Being existing in three co-equal Persons. Modifications to this doctrine inevitably result in the worship of a false god.