A bare theism that denies God’s ability to join himself with his creation is an impoverished worldview that is not only unfaithful to Scripture but also undermines both the omnipotence and immanence of God.

[The first five installments of this series are available at Part 1, Part 2, Part 3, Part 4, Part 5. Part 6, below, concludes the series.]

Unitarianism refers classically to the Christian heresy that God is a single person (hence, no Trinity) and that Jesus Christ is an exalted man. The doctrine originated in the sixteenth century and found formal theological expression in the writings of Laelius Socinus and especially his nephew Faustus Socinus. The term Unitarianism is also often used for modern versions of Arianism, the fourth-century doctrine of Arius of Alexandria, which affirms that Christ existed before his human life. The best-known advocates of this doctrine today are the Jehovah’s Witnesses, whose view of Christ we discussed in an earlier installment of this series. Socinianism, on the other hand, denies any such preexistence of Christ. Our focus in this article is on the Socinian form of Unitarianism.

In the eighteenth and nineteenth centuries, most Unitarians became increasingly liberal in their theologies. Mainstream Unitarianism in Britain and the United States dispensed with the infallibility of the Scriptures, the virgin birth of Christ, and eventually practically every major element of Christian doctrine. The Unitarian-Universalist Association that emerged in the twentieth century is now so liberal that only a minority of its members even profess to be Christians or to believe in a personal God.

In the late twentieth century, classic Unitarianism began enjoying something of a revival. These Unitarians often refer to themselves as Biblical Unitarians, largely to distinguish themselves from Unitarian-Universalists. They affirm the authority of the Bible and espouse a theistic worldview. They agree that God is a personal being and the Creator and Ruler of all things. They also accept such traditional divine attributes as omnipotence and omniscience.

Unitarians agree with historic Christianity that Jesus was born of a virgin, died on the cross for our sins, rose from the dead, and ascended into heaven. However, they deny that Christ existed in heaven before his human life. Only when Jesus ascended into heaven, according to Unitarians, did he become divine, and even then in a subordinate role to the Father, who alone is the real God.

Denominations espousing this Unitarian theology include the Christadelphians and the Church of God General Conference. Anthony Buzzard is the movement’s best-known theologian and Dale Tuggy its best-known philosopher.^[1] In 2019 Tuggy and others founded the Unitarian Christian Alliance to foster fellowship among Unitarians as well as to defend Unitarian belief.

What “Biblical Unitarians” and liberal Unitarians have in common is a rationalistic insistence on the strict application of logic (as they understand it) to theology. While Unitarians do claim biblical support for their doctrines, their criticisms of the doctrines of the Trinity and the incarnation focus on their supposed irrationality. For example, Buzzard criticizes the doctrine that Jesus is both divine and human by stating flatly, “One person cannot at once be both infinite and finite.”^[2] He dismisses the very idea of the incarnation as an “impossibility”:

Someone who was fully God and fully man cannot be totally human. This is the root of the Trinitarian problem. It is a sheer impossibility, in biblical terms, to confuse the One God with a human being.^[3]

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