I’ve often found in the course of my studies that there really is such a thing as “lost in translation.” It’s easy to assume that we understand enough from the English versions of our Bibles, and as far as daily life is concerned, I’m still of the mind that this is correct. But when it comes to thorny questions, when we get into the nitty gritty of our studies, it’s helpful to dig a little deeper, look at the original languages where possible, and often times, search out the original context.
While I was searching for greater understanding of some of the prophecies of the minor prophets, I bumped into this article that explains the concept of the plurality and unity of God in a way that was far clearer and more comprehensible to me than any Protestant Christian explanation of the Trinity I had yet encountered. It made sense of certain Bible passages and events in the Old Testament that had formerly been points of confusion for me, including the varied translations of Nebuchadnezzar’s words concerning the Angel of the Lord vs. the Son of God in the fiery furnace.
In short, the concept of the Trinity is not founded in the New Testament at all, but in the Old. The Father, the Son, and the Holy Spirit, if not presented in precisely those terms, is clearly presented in the Jewish Scripture.
I heartily recommend this article for a clearer picture of the Biblical nature of God.
Jewishness and the Trinity by Arnold Fruchtenbaum, published on the Jews for Jesus website