The following was written in 1825 by Samuel Barrett (Boston: American Unitarian Association).
Unitarian Christians believe Jesus Christ to be the Son of God and the Saviour of men. They believe in the divinity of his mission and in the divinity of his doctrines. They believe that the Gospel which he proclaimed came from God; that the knowledge it imparts, the morality it enjoins, the spirit it breathes, the acceptance it provides, the promises it makes, the prospects it exhibits, the rewards it proposes, the punishments it threatens, all proceed from the Great Jehovah. But they do not believe that Jesus Christ is the Supreme God. They believe that, though exalted far above all other created intelligences, he is a being distinct from, inferior to, and dependent upon, the Father Almighty. For this belief they urge, among other reasons, the following arguments from the Scriptures.
1. Because Jesus Christ is represented by the sacred writers to be as distinct a being from God the Father as one man is distinct from another. “It is written in your law, that the testimony of two men is true. I am one who bear witness of myself, and the Father that sent me beareth witness of me,” John 8:17, 18.