There is a major religion today that holds to this modalism concept?I can't remember who, offhand?Moon's
Unification Church?
I don't see how the Bible can be used to support modalism, but it can be used to support Trinitarianism.
I think there is a problem if we demand that the Father and the Logos (John 1:1) are exactly the same in every way. I don't think the Bible text requires that. What the writers did want us to see was that Jesus was in complete harmony and unity with the Father, and had the same authority over all creation that the Father did in the OT. In that regard, it would be perfectly acceptable to refer to Jesus as God. Although John is the most overt about this assertion, the other Gospels make it a point to note events where the actions of Jesus are consistent with those of God in the OT. It also seems consistent with the rest of John's Gospel that he would assert that "God was the Word (logos)" and not "a god... ," so that the Logos shared in God's nature.
Now I may be deviating a bit from traditional orthodox teaching here, but as I read it, Jesus can be called "God" because of his dual nature: body and spirit. The Bible teaches that each of us has a dual nature: the physical body and the spirit. (It may even be considered a trinitarian nature, if you want to include the soul as separate. For the sake of simplicity, I would only differentiate between natural/physical/material and supernatural/non-physical.) Each one of us is a body and a spirit?together, they constitute the individual, and yet, either one of those constituents could be referred to as that individual (When we refer to a person today, say Billy, for example, we would normally be talking about him in his physical form. Yet, scripturally, it would also be appropriate to refer to Billy's non-physical essence by his name.) I see the spiritual component of Jesus as the Logos (God), so it would be completely proper to refer to him as man (Jesus of Nazareth, born of Mary), or God (Logos in him?but please don't call Mary the "mother of God.") While on earth, though, he functioned as a man. During his ministry on earth, he operated pretty much as an OT prophet?relying on the Holy Spirit for insight and power. One area he operated as God was in his authority?in his teaching, and over the natural and supernatural realm, but the power came by the Holy Spirit. Consequently, he was subject to many limitations. Although he was always aware of his relationship to the Father, he operated under these restrictions or limitations to meet the requirements as the "second Adam." Therefore, it is appropriate for him to pray to the Father and to call Him his God. Even now, in his glorified state, he is still retains a bodily form (and I mean a resurrected, physical body, although it is no longer subject to the limitations of our physical laws) and is subject to the Father in some manner. He is a glorified man and yet more.
To be comfortable with the concept of the Trinity (I think tri-unity may be a better term), we have to get out of our limited way of thinking about the universe?limited by our own restrictions of what we are able to perceive, how we process that information, and the models we construct to process further information. The more we learn about the universe, though, the more we realize there is so much we don't know. We become better able to "think outside the box," or at least accept there are things we can't know with the current technology we have. Consequently, we have passed from simply accepting things on pure faith, to rejecting them because they can't be explained or tested scientifically, to recognizing that they may exist, but we just can't verify them at this time. We are now advancing beyond the limitations that confine things to the context of a four-dimensional universe. Science fiction has always been on the cutting edge of this frontier, and what is sci-fi today can be reality tomorrow. The idea of a single entity being manifested in multiple forms is a hard concept for us to accept because it just doesn't happen in our limited experience. One person is one person, manifested in one form. Multiple manifestations have always been hard to explain or depict. I notice the WT has used illustrations from artwork to refute the Trinity by appealing to the apparent absurdity of the artwork?three-headed men, etc. But that is attacking a straw man. Ridiculing the work of medieval artists does not refute the Trinity. So what happens if we set aside our medieval thinking and open our minds to accepting the possibility of a parallel dimension?the spiritual world, including heaven?where God is not confined to a single manifestation, i.e. the Father, but can simultaneously exist with the Logos (indwelling Jesus Christ since the incarnation), and the Spirit? These three can have some differences between them, but share a common nature and are called God. Three "persons" are all entitled to be called "God"; all three collectively constituting God, yet each individually deserving of the title of God. Is this really so incredible, then?