Please read A Disclaimer first.
Briefly stated, Categoricalism posits that Yeshua was made by God to represent him–to be the final and complete image, form, appearance, proxy, or avatar of YHWH. Yeshua is thus the category of God, but not ontologically God. Categoricalism takes for granted that YHWH is one person (not three) and that Yeshua is not that person, yet allows for Yeshua to be considered divinity in that he was uniquely chosen by YHWH and made by YHWH to represent him. Thus, to speak of the man Yeshua is to speak of the god YHWH. To follow the man Yeshua is to follow the god YHWH. And to be saved by the man Yeshua is to be saved by the god YHWH.
All this is based around a Hebraic concept that one person can be identified as another without literally or ontologically being the other. A person is understood to stand in the other’s place and be the category of the other (thus, for instance, you have Peter referred to as Satan1, Satan referred to as God2, Moses referred to as God3, and numerous other examples). This is further explained by the concept of agency as we find it even in the earliest Rabbinic halacha, a man’s agent is as himself.
The saying does not speak ontologically, of course, but categorically. The one who is sent is viewed as if he is the other.
A man’s agent is like to himself.
Mishnah, Tractate Berakoth 5:5
In all circumstances do we find that a man’s representative is equivalent to himself.
Babylonian Gemara, Tractate Nazir 12b
We find in the whole Torah that a man’s agent is as himself.
Babylonian Gemara, Tractate Nedarim 72b
A man’s agent is as himself.
Babylonian Gemara, Baba Mezi’a 96a
It is logical that the hand of a slave is as the hand of his master.
Babylonian Gemara, Baba Mezi’a 96a
Although the agent remains subordinate to the sender, the agent and sender are considered equal to any third party. The agent has the same rank and authority as the sender. Whatever authority or rank a sender lacks cannot be held by the agent. They are one. So much so that, as the expression goes, when the agent speaks, it is as if the one who sent was speaking.
We need not wonder, therefore, how Yeshua, if only a man, could pronounce verily I say
instead of thus says YHWH,
for if Yeshua is uniquely YHWH’s agent and representative, his words should be considered YHWH’s.
The agent can do all that the sender can do. That which a sender cannot do, the agent cannot. The question, therefore, is not whether a mere man can bring salvation, can receive glory, can be worshiped, or the many other objections people have to Yeshua having divine status without being YHWH himself. The question is, rather, can YHWH bring salvation, receive glory, or be worshiped? If so, then he can appoint one in his name to bring salvation, receive glory, or be worshiped, for such is considered done by or to YHWH himself.
If an agent acts or speaks without having identified themselves as being sent or without having identified their sender, then such is considered done on the part of and by the individual themself. However, if an agent does provide this information, the representative nature is understood and such an idea as them claiming something of themselves and for themselves is untenable. If Yeshua were YHWH’s unique agent and representative, we would expect to find a proclamation of Yeshua’s agency and representation in the New Testament. And if we were lucky enough to find Yeshua describing this exact agent/sender relationship as we’ve already explored in terms of himself and God, we would know that Yeshua means for us to understand him in this way and not according to Trinitarianism and the Hypostatic Union. Surprisingly, the evidence is staggering (unequivocal claims of agency in CAPS):
Whoever receives you receives me, and whoever receives me RECEIVES HIM WHO SENT ME.
Matthew 10:40
Finally, HE [YHWH] SENT HIS SON [Yeshua].
Matthew 21:37
HE HAS SENT ME TO PROCLAIM liberty to the captives and recovering of sight to the blind, TO SET AT LIBERTY those who are oppressed.
Luke 4:18
The one who hears you hears me, and the one who rejects you rejects me, and the one who rejects me REJECTS HIM WHO SENT ME.
Luke 10:16
My food is TO DO THE WILL OF HIM WHO SENT ME and TO ACCOMPLISH HIS WORK.
John 4:34
I CAN DO NOTHING ON MY OWN. As I hear, I judge, and my judgment is just, because I seek not my own will BUT THE WILL OF HIM WHO SENT ME.
John 5:30
For THE WORKS THAT THE FATHER HAS GIVEN ME TO ACCOMPLISH, the very works that I am doing, bear witness about me that THE FATHER HAS SENT ME.
John 5:36
So Jesus answered them,
MY TEACHING IS NOT MINE, BUT HIS WHO SENT ME.John 7:16
And Jesus cried out and said,
Whoever believes in me, BELIEVES NOT IN ME BUT IN HIM WHO SENT ME.John 12:44
For I HAVE NOT SPOKEN ON MY OWN AUTHORITY, BUT THE FATHER WHO SENT ME has himself given me a commandment—what to say and what to speak.
John 12:49
And we have seen and testify that THE FATHER HAS SENT HIS SON TO BE THE SAVIOR of the world.
1 John 4:14
Those are just a sampling. Clearly, Yeshua is portraying himself to be not the literal nature and person of God himself, but is instead specifically using terms which describe himself as the functional representative and agent of God. He does not speak his own words but the words of his sender. He does not do his own deeds but the deeds of his sender. He has no authority other than the authority of his sender. But if they accept him, they accept his sender. If they believe in him, they have belief in his sender. If they know him, they know his sender. Et cetera. And clearly this concept was of primary concern. He even claims that believing himself to be the agent of YHWH is the marker of eternal life!4 To say that Yeshua used specific words again and again that meant one thing to his audience (agency) but really meant something entirely different (Trinitarianism and the Hypostatic Union) is not only to beg the question, but to make a mockery of the text.
Even in modern times we understand and utilize this concept of agency. No one would be confused if I said I watched and heard President Bush give a speech last night despite the fact that I was not actually in contact with the literal person of President Bush and even though I didn’t actually hear his voice. I watched thousands of flickering points of light on a television monitor and heard sounds created by pulsating speakers. The monitor light and speaker vibration represented Bush and his speech-giving in such a way that I can truthfully say I heard and saw him. In like concept then, YHWH made Yeshua to become his image and glorified him by giving him a name above every other name (his own) without Yeshua ever being God of his own self or being5. Our modern systems of jurisprudence have also incorporated this concept. If I were to appoint a man to marry a woman for me by proxy and she accepted, his vows, his presence, his signature, and his completion of the ceremony would be considered my own. Even if I had never met the woman, we would be legally wed.
Categoricalism has many further advantages. For one, it makes sense of every theophany without turning YHWH into something he isn’t or turning something that isn’t God into him and does so simply without need of complicated and arbitrary theological formulations. It allows one to call the burning bush a form or image of YHWH, the pillar of fire a form or image of YHWH, the Shekinah a form or image of YHWH, and so on and so forth up to Yeshua himself as the final and complete representation without having to delimit divinity. We need not wonder, for example, that all three visitors to Abraham are called by the divine name reserved only for the Father and that all three are worshiped by the Patriarch while simultaneously being called men.6 Likewise, we are not confounded by the messenger who speaks one moment as someone and something other than YHWH and the next, without qualification, as YHWH himself.7 For another, it requires no distortion of scriptural data. So, for instance, the Categoricalist need not create terms like God the Son
in replacement of scriptural ones like Son of God.
And when referring to a scriptural term like Son of God,
the Categoricalist need not define it in a way foreign to the text or its ancient Near Eastern background. Instead of understanding it as speaking of the philosophical makeup of a person’s ontological being or descriptive of their own personal divinity, which is nowhere present in scripture’s use of the term, it defines Son of God as scripture does: generally as either a righteous person or Israel herself and then specifically as Israel’s representative head, Messiah, or King.8 In fact, the idea of divine sonship as applying to the election of a human figurehead was quite common in ancient Syria and Palestine. So, for instance, we find that the kings of Damascus in the ninth century BC were titled “Son of Hadad” (Hadad being another name for the Canaanite god Baal) and at least one Syrian king was called “Son of Rakib” after the god Rakib-El.9
If this were all (and it is not), it would be more than enough for Categoricalism to make better sense of Hebraic perspective, ancient culture, and scriptural text than Trinitarianism. But since this theology is especially hard for Orthodox
Christians, fundamentalists, and proof-texters to accept, I offer up in conclusion a small but powerful list of passages in the New Testament that are not only misleading, but outright contradictory if meant to convey to its readers that Yeshua is and should be known fundamentally as YHWH himself. Instead, these verses literally define and speak of Yeshua as something other.
He is the IMAGE [not the actual person or literal divine being] of the invisible God.
Colossians 1:15
He is the REFLECTION of God’s glory [instead of the source or origin] and the REPRESENTATION of God’s being. [instead of God’s being, essence, or nature itself]
Hebrews 1:3
who existing in the FORM of God . . . [instead of the person or literal being of God]
Philippians 2:6
who is the IMAGE of God. [instead of the person or literal being of God]
2 Corinthians 4:4
1Matthew 16:23; Mark 8:33; Luke 4:8
2Chronicles is well-known and agreed to be a later revision of various documents including portions of Samuel-Kings. The identification of Satan as God is made through the manner in which 1 Chronicles 21:1 re-envisions 2 Samuel 24:1. The earlier Samuel passage describes God provoking David to take a census (perhaps similar to the hardening
of Pharaoh’s heart). When Chronicles later revisits the story, it says that Satan was the one who provoked David to take the census. Most Christian interpreters have had no qualms harmonizing the possible discrepancy by saying one can identify Satan as God because Satan is acting on behalf of God (therefore to speak of Satan acting is to speak of God acting), but have given no reasons why the Chronicler should have had this theological assumption in mind rather than something else. Such smoothing of the text was probably done in order to maintain a doctrine of the inerrancy or infallibility of accepted scripture. I propose that this explanation makes the most sense in terms of the basic proposition of Categoricalism.
3In Exodus 4:16, YHWH describes a kind of role exchange in which he will make Moses be God to Aaron and Aaron will, in turn, be Moses to Pharaoh by doing the things Moses should do but clearly isn’t willing to.
4John 17:3.
5Bush is mentioned only arbitrarily. No similarity is implied or presumed between the persons, beings, or activities of Bush and Yeshua.
6See Genesis 18 through 19. This story has constantly proven difficult for Trinitarians throughout history, but is simply and easily explained by Categoricalism.
7There are a myriad examples in the Hebrew Bible of a prophet, angel, or someone else speaking as if they were someone other than God one minute and then suddenly—sometimes mid-sentence—changing the way they speak, what they say, or how they act so that they are no longer differentiated from, but identified as God himself. One classic example is a being referred to as the Angel of the Lord
in Genesis 22:12 who says he knows that Abraham fears God because Abraham was willing to sacrifice his son to God, but ends the sentence by identifying himself as the one to whom Abraham was offering sacrifice. It is clear from texts like this that identifying someone as God himself does not require their own personal ontological divinity. And yet Trinitarians will suddenly change the rules of the game when it comes to Yeshua and say that it does.
8Examples include Exodus 4:22; Hosea 11:1; Psalm 2; 2 Samuel 7:14; Wisdom of Solomon 2; 18:13; Joseph and Aseneth 6:2, 6; 21:3; Jubilees 2:20; 4Q246; 4Q504 3.4-7
9See Introduction to The Hebrew Bible by John J. Collins, p. 235.

Steve Says:
What about 1 John 5:7
"For there are three that bear witness in heaven: the Father, the Word, and the Holy Spirit; and these three are one."
The Word is clearly described as Jesus Christ in the gospel of John 1:1-14.
slaveofone Says:
You bring up a very interesting verse. This is called the Comma Johanneum. The short answer is that all our evidence points to this verse being added to the scriptures three or four hundred years after Christ and should not be considered authentic. Although I am not one to support the use of Wikipedia, if you go there (http://en.wikipedia.org/wiki/Comma_Johanneum), you will find a somewhat okay description of what’s going on with that verse. You can also google "Comma Johanneum" and that should bring up a lot of places where you can read about the issue.
Yes, the Word is clearly described as Jesus in John’s gospel. The Word is also clearly described as the Torah scroll in Baruch 4:1 (probably written around the time of Yeshua) and in Ben Sira 24 (written about 200 years before Yeshua). In fact, John 1:1-14 borrows what he says about Yeshua as the Word from Ben Sira, even using the same Greek words. I can go into a lot of detail about that, but I won’t here. Simply put, the Word becoming flesh and tabernacling in Israel didn’t make the Torah Scroll part of the Trinity in Ben Sira and therefore it does not in John…unless you’re willing to say the Torah Scroll is a Person in the Trinity, of course :)