Such an important subject matter like the Trinity and the Bible is silent on all of it...
It seems it would have been clearly stated in the Bible and in the earliest Christian creeds if the doctrine of the Trinity was genuine and central to Christian belief and especially if belief in it was necessary for salvation as many Trinitarians teach. God gave the Scriptures to the Jewish people, and the Jewish religion and worship that comes from that revelation does not contain any reference to or teachings about a triune God. Surely the Jewish people were qualified to read and understand it, but they never saw the doctrine of the Trinity.
If there is a trinity then why not just come out and say it? Why do we have to jump all over the Bible cutting and pasting pieces of words that are scattered all over the Bible? Why not just teach it? I know enough about how the Bible is written in the New Testament and in the Gospels to know if there was a trinity it would have been taught.
There's reasons why the Bible does not teach the Trinity in one whole paragraph in a few different places or a whole chapter or two on it. There's reasons why there's no teaching on why God would come to the earth as a man. There's reasons why there was never a debate about the Trinity in Scripture like we see with justification by works or who should be circumcised. There's reasons why there's no verse in the Bible that says we should believe or confess that Jesus is God.