Throughout the history of the Christian church there have been other views brought forward to explain the nature of God that have fallen short of what the Bible says. One of these is Unitarianism.
The Beliefs of Unitarianism
Unitarianism holds to the belief that God cannot be properly spoken of as existing in three persons. God is rather a unity, one in essence and person.
Unitarianism dates back to the fourth century when Arius, a bishop from Alexandria, denied that Jesus was the eternal God. Arius taught that Jesus' nature was greater than man's but less than God's. He also denied that the Holy Spirit was God.
Socinius
Modern Unitarianism dates from the sixteenth century to a man named Socinius. To Socinius, the death of Christ on the cross for the sins of mankind was unnecessary. Rather than believing that Jesus was a divine Savior, Socinius taught that God raised Jesus to divine power as an act of loving-kindness to His people.
Jesus Had a Special Commission
Although they rejected the doctrine of the Trinity, the Unitarians of the seventeenth and eighteenth century viewed Jesus as one who had a special commission from God. They taught that Jesus revealed truth from God that man, through his reason, would not otherwise know. The nineteenth century saw a shift in the Unitarian position. Influenced by the German higher criticism of the Bible, a school of thought developed within Unitarianism that was anti-supernatural. They came to doubt the four gospels as authoritative sources and rejected the uniqueness of Christianity. This rejection of Christianity's uniqueness was something that earlier Unitarian belief had also held. But with the anti-supernaturalistic attitude, the goodness of man was stressed more than the existence and power of God.
Not Any One Set of Beliefs Today
Today Unitarianism does not ascribe to any set of beliefs. What binds Unitarians together is a basic belief in the goodness of man and that God is not limited to any one particular revelation, such as the Bible, but can be found in many different religions.
Summary
Modern Unitarianism goes back to the 16th century. It holds to the belief that God cannot be properly spoken of as existing in three Persons. To the Unitarians God is rather a unity, one in essence and person. Unitarianism is an inadequate view of God's nature. It argues for the unity of God but rejects the idea that God is a Trinity. Consequently the Unitarian view of God is contrary to what Scripture clearly teaches. It either denies or misunderstands what the Bible has to say about the nature of God. Present-day Unitarians do not subscribe to any one set of beliefs.