” The doctrine of the Trinity is essential to Christianity”
The article teacthes; “ St. Paul emphasizes, over and over again, the importance of teaching in accord with sound doctrine.”
“Trinity” is a title added to God’s Word to explain and translate the confusion between scriptures that say Heavenly Father and Jesus are one and scriptures that say Jesus is subordinate to His Father, but not part of the Father. It is a definition added to scripture.
You also say; “ If you do not believe Christ is one with the Father and the Holy Spirit you are not a Christian.”
Why was it not explained and translated that Jesus and God the Father had a plenipotentiary relationship?
By what authority has this definition Trinity been added to the Bible?
In the beginning was the Word. And the Word was with God and the Word was God. Sorry but your mormon heresy is not part of Christianity
“ By what authority has this definition Trinity been added to the Bible?”
It was never added to the Bible.
It is a descriptive name of the teachings that in the Bible.
In the same way the word “bible” is never found in the Bible...
But we know what it means when it is used.