My God, my God, why hast thou forsaken me?

[Crossless2.0]

I agree.

I think it's equally stupid to pretend that the doctrine is necessarily baked into Christian belief or was there from the beginning of the movement, and not something cobbled together as a "solution" to a long-standing problem for the church. The number of people who subsequently embraced the doctrine, after the church had effectively labeled alternative understandings as heresies and rooted them out, is neither impressive nor compelling.

That's a very bad argument. Of course the doctrine of the Trinity is baked into Christian belief. ALL the support for it comes from the NT. Here's the test: would anyone trying to work up a systematic theology from the NT words of Jesus and overall events come to a different conclusion if they did not know anything about traditional theology? The answer is no--because it would have happened by now. The NT is the most carefully studied group of documents ever. The doctrine of the trinity is practically universal.

I said "necessarily baked into Christian belief" and stand by that. Of course the Trinity is derived from the NT (specifically out of a need to square John's high-Christology with those gospels that don't embrace it) but it's simply historically false to suggest that this was the only possible outcome of that effort. There were several previous theological positions meant to answer the same problem. I suspect a big reason you don't see people today widely and spontaneously embracing Docetism, to take but one example, is that this view was proscribed centuries ago and subsequent generations of priests, ministers, and laypeople have simply inherited the view that "obviously" the Trinity is the only sensible answer left standing. But councils of priests settling on one answer in a dispute that amounts to little more than imaginative literary criticism (the polite version) or mental masturbation (the less polite version) and declaring alternative viewpoints to be heresies doesn't fill me with much confidence.

You believe it. That's nice for you. But your belief is, itself, historically contingent. Left to your own devices and a NT, I rather doubt you alone would have stumbled across this particular solution.