Granted with a caveat. Since the trinity is a doctrine that evolved over several centuries after the death of Christ by what became the Catholic church. Protestants decided to keep this tradition. However the trinity doctrine isn't a "Christian" belief, rather it's a TRADITIONAL Christian belief. There's no doubt that bible Christians had no clue that a trinity doctrine was going to developed.
I would be glad to identify myself as a biblical Christian or a 1st century Christian to make that distinction clearer.
About one thousand different sects claim to be authentic "biblical Christians" or "1st century Christians."
The Primitive Baptists, the LDS, Oneness Pentecostals, Orthodox Presbyterians, United Church of God, the Church of Christ, the Disciples of Christ, Iglesia ni Cristo, the Marcionists, and many, many others love to make or have made this claim.
Yet they all have deeply different beliefs and distinctives.
Very few people, however, realize how radically arrogant this claim is.