I am having a discussion with a Christian friend and I stated that my issue with the trinity is that the trinity has never been mentioned by name in the Bible, nor is there a doctrine of the trinity found within the Bible, and in that regard questioning how someone come to the belief that such a fundamental tenant of faith and salvation was chosen to not be highlighted clearly and without question. Stating the seemingly odd nature that God ordained such a core belief in his divine system or ordinance 300 or odd so years after the departure of Jesus Christ within The council of Nicaea.
His response was that the trinity was introduced when Moses spoke with God at the burning bush and how that was the word or spirit of God
What is a clear stance that can be taken to highlight the unbiblical nature of the trinity, as well as a well rounded rebuttal to the assertion that it was highlighted through the burning bush.