The whole concept of The Holy Trinity (they being of one body) came from a vote in the Nicaean Creed in the 4th century after Constantine adopted Christianity as the official Roman religion in order to quell the divisiveness. It's man-made doctrine, we just happen to believe that God, his son, and the HG are all separate individuals, united in purpose. We worship God through his son JC with JC being the mediator.
Isaiah 43:10 | English Standard Version
10 “You are my witnesses,” declares the Lord,
“and my servant whom I have chosen,
that you may know and believe me
and understand that I am he.
Before me no god was formed,
nor shall there be any after me.