Unitarianism
In one sentence
An anti-Trinitarian position holding that God is one Person.
In simple terms
God is understood as one Person; the classical distinction of Father, Son, and Holy Spirit as three eternal Persons is rejected.
Biblical truth
Scripture clearly affirms that God is one; at the same time, the New Testament distinguishes Father, Son, and Holy Spirit and attributes divine qualities and works to the Son and Spirit.
Key Scriptures
Deut. 6:4 · Matt. 28:19 · John 1:1–3 · John 17:5 · Acts 5:3–4
Example
A Unitarian reading commonly takes “the Father is greater than I” as confirmation that only the Father is God in the fullest sense.
Who holds it
Historical and modern Unitarian movements; their specific views of Jesus vary.
Opposing view
Trinitarianism
Not to be confused with
Not to be confused with biblical monotheism in general: Trinitarians also confess one God.
History
Anti-Trinitarian forms appeared in different eras; organized Unitarianism developed especially after the Reformation.
Main point of debate
The central dispute is whether biblical divine unity requires one divine Person or is compatible with three eternal Persons.