The fundamental difference between biblical Christianity and Oneness theology is this: the Oneness view of God holds to a unitarian starting point, namely, the assumption that monotheism equals unipersonalism.

First, since Oneness doctrine asserts a unipersonal God without the distinction of three Persons, it sees Jesus then as the mere “name” of the unipersonal deity, who manifested as the modes or roles of the Father, Son and Holy Spirit, thus denying the unipersonality of Jesus Christ. Second, since it asserts that only the Father is God (i.e., Jesus’ divine nature/mode), the “Son” represents only Jesus’ human nature/mode, thus denying the Son’s deity. Third, since it rejects the idea that the Son is God, Oneness Christology denies (a) the Son’s pre-existence, (b) the Son’s active role as the agent of creation (the Creator), and (c) the Son’s eternal and intimate relationship with the Father. Pertaining to redemption, Oneness doctrine maintains that Jesus as the Father took flesh, hence denying the incarnation of the divine Son.

In contrast, an exegetical analysis of particular biblical passages in both the Old and New Testaments establishes the fundamental data for the doctrine of the Trinity. Hence, Scripture reveals in the clearest way that there are three distinct Persons—the Father, the Son, and the Holy Spirit—that share the nature of the one God. Thus, the three Persons are co-equal, co-eternal, co-existence, and co-distinct. The full deity, incarnation and pre-existence of the Son, as a distinct Person from the Father, are especially expressed in the Apostle John’s writings.

In the Pauline corpus, the deity, unipersonality and distinction of all three Persons are seen frequently either in the same passage or same context. Both John and Paul present the Son as God and Creator of all things. In the prologue of Hebrews, the author asserts clearly and coherently that the Person of the Son is the eternal Creator; this assertion demolishes the Oneness position, which sees the “Son” representing only the human nature of Jesus whose life started in Bethlehem. This work concludes that the concept of the Trinity is inescapable in the light of biblical exegesis. Oneness theology cannot stand exegetically. It must circumvent and redefine the plain reading of many passages that state or imply, for example, the grammatical and contextual distinctions of the Persons in the Trinity, the pre-existence and deity of the Son, and the deity and unipersonality of the Holy Spirit.

Lastly, contrary to the historical revisionism frequently employed by Oneness authors and teachers, the early church prior to Nicea held to the concept of the Trinity universally rejecting both modalistic and dynamic forms of Monarchianism.   

In light of the theological views of Oneness theology, we must evangelize Oneness believers. We must proclaim to them the truth of the Jesus Christ of biblical revelation. And we must pray for them praying that God saves them and makes them alive to the gospel of the Son, “the true God and eternal life” (1 John 5:20).