A fundamental point that connected all those who embraced the concept of the Holy Trinity in the way that we now understand the term (or close to it) argued that the multiplicity of councils in this century and the next that addressed the nature of the Trinity did not create doctrine or orthodoxy (or even uncover them). Rather Trinitarians supported the importance of the range of councils as the proper method to respond to the heresies that they believed were rumbling through the church and threatening to drown the voices of the orthodox. Many of the heresies (to the Trinitarians, of course) of the time revolved around the nature of God as the Trinity (Williams 23-5).
One of the most important of these heresies was that of Arianism, which roiled the church between the Council of Nicaea (in 325) until the years after the Council of Constantinople in 381. At the center of Arianism and this era of negotiating and renegotiating the nature of the fundamental terms and concepts of the Christian church was the exact relationship between God the Father and Jesus, or God the Son (Williams 21).
Arianism arose in some measure from the fact that the early church was influenced by (or perhaps more accurately awash in) Platonism -- a birthright of the church's early history in a classical city. Fundamental to Platonic thinking was the idea of a "first cause" that created a sense of both organization and hierarchy throughout the universe. For the Platonist, everything flowed from this first cause. This might seem to be concordant with Christian teaching (and with Trinitarian thinking), for the "first cause" of the universe can be understood as the Christian God (Williams 42).
From this first cause (one could argue, following both Christianity and to a lesser extent Platonism) that God the Son (also conceptualized as Logos, the word of God) was created by this first cause -- and was equally divine. The Holy Spirit could then (still in keeping with both Christianity and more-or-less with Platonism) be seen as a further development of the divine nature and essence of the first cause -- or God. However, what Arianists argued was that the Son of God was not in fact divine in the way that God is. And if this were to be the case, then the idea of the Trinity would no longer be valid.
Followers of this doctrine were no doubt attracted to it in part because it aligned with their understanding of Greek philosophy (which was a relatively unsophisticated one) as well as because it coincided with the historical facts of Jesus. Clearly Jesus (as God the Son) follows in terms of time and history God the Father. That this should somehow make him lesser, that this should someone make him other than divine, was the interpretation that the Arianists pursued (Williams 291). This was clearly not the only possible resolution to this theological question (obviously -- as I have been arguing throughout this paper in support of the Trinitarian position) and it does not surprise me that the Arianist position relatively quickly faded.
Platonism creates a world that is hierarchical and highly ordered, a world in which divinity could be sliced into unequal parts -- something that we see in the Greeks' own pantheon. This position could not be reconciled with the idea of the three aspects of divinity -- God the Father, God the Son, and God the Holy Spirit -- as being equal at all levels and in all ways (Erickson 23).
Old Testament Precedents of the Trinity
It is noteworthy that there exists what might be seen as both a theological and semantic antecedent to the concept of the divine Trinity in the Old Testament. While some sects of Christianity are what seems to me as dismissive of the Old Testament, I do not believe that this is a productive or authentic approach. There are important links between the Old and New Testaments; furthermore, I believe that whatever tools are at hand that allow one better to understand the nature of Christian teachings should be used. While some Christians speak as if they wish they could cast off the Old Testament in the same way (and for much the same reasons and with the same speed) that would cut off a gangrenous limb, I believe that a full understanding of Christian faith, belief, and practice can all be informed by a careful perusal and reading of the Old Testament.
In this line, I would like to note that there are Old Testament references to the Wisdom, Word, and Spirit of God, which can in some important ways be seen as a precedent to the underlying concept of the Trinity (Letham 81-6). I would also argue that there is a connection between the Trinity and Abraham's encounter with the three men in Genesis 18:
1 The LORD appeared to Abraham near the great trees of Mamre while he was sitting at the entrance to his tent in the heat of the day.
2 Abraham looked up and saw three men standing nearby. When he saw them, he hurried from the entrance of his tent to meet them and bowed low to the ground.
3 He said, "If I have found favor in your eyes, my lord, [a] do not pass your servant by. 4 Let a little water be brought, and then you may all wash your feet and rest under this tree. 5 Let me get you something to eat, so you can be refreshed and then go on your way -- now that you have come to your servant." "Very well," they answered, "do as you say.
Likewise, the divine messenger that appears in several Old Testament passages has also been interpreted by some people as support for the Holy Spirit as an aspect of a Trinitarian God (Erickson 31).
Among these passages are Genesis 16:7 ("The angel of the LORD found Hagar near a spring in the desert; it was the spring that is beside the road to Shur.); Genesis 21:17 (God heard the boy crying, and the angel of God called to Hagar from heaven and said to her, "What is the matter, Hagar? Do not be afraid; God has heard the boy crying as he lies there.); and Exodus 3:2 (There the angel of the LORD appeared to him in flames of fire from within a bush. Moses saw that though the bush was on fire it did not burn up). Another passage that suggests strongly at the complex nature of divinity without being explicit about the Trinitarian nature of God comes in Leviticus 9:4: "And an ox and a ram for a fellowship offering to sacrifice before the LORD, together with a grain offering mixed with olive oil. For today the LORD will appear to you."
I believe that passages such as the above (there are other similar passages that I am not citing here since they are very similar to those above) do provide a theological basis to what will develop into the completed concept of the Trinity. Not only do these concepts seem to me to be spiritually (as well intellectually and emotionally) attuned to the Christian concept of the Trinity, but I believe the fact that the concept of the Trinity was already essentially present in the Old Testament explains in part what to me has always been a somewhat puzzling aspect of the importance of the Trinity to Christian orthodoxy: The idea (and reality) of the Trinity is never made explicit in the New Testament (Erickson 21).
It seems to me to be possible that such an omission might be based on the fact that the idea was already current. Let us consider the possibility that early Christians were familiar with the idea of God as a complex personhood from their familiarity of the nature of the divine from Jewish practice. If we begin with this perspective, then it becomes possible and even something close to probable) that members of the early Christian church might have been inclined to discuss (and revere) the Trinity in more implicit terms. If the first Christians were already inclined to think in trinitarian terms (although not Trinitarian terms), then they might not have felt the requirement to discuss the Triune nature of God in explicit terms. It might have been something that was (to some extent) simply expected (and accepted) among early Christians.
(I should note here that I am, of course, not arguing that Old Testament ideas that suggest at a more-than-unitarian nature to the divine are not very different from the Christian Trinity. Nor am I suggesting that there is a direct connection between the ideas behind the passages cited above and the fully developed concept of the three-in-one God (Erickson 49). I am positing not so much direct connections as indirect links. If Jewish thought was not as absolutely and purely monotheistic…