The early church in it's simplicity and simple faith in God, believed in ONE God; and that God was all in all to them. He was their Father in creation, their Saviour manifested in Jesus Christ and their Salvation in the form of the Holy Spirit "in" them. It was not until the death of the "original" apostles, and false apostles (Rev 2:2) entered the church, that the Godhead became an issue. These false apostles began to bring heresy into the church, attempting to "organize" the Christian Faith and exercise "control" over the laity. Such control and domination is not of the Spirit of God but is of the spirit of witchcraft. And that same spirit has been demonstrated by a few on this form on many threads especially pertaining to the subject of the Godhead. In Revelation 2:6 Jesus identified this in the first Church Age (Ephesus) as "the deeds of the Nicoliatanes". By the third Church Age (Pergamos) these "deeds" had become a "doctrine", called "the doctrine of the Nicolaitanes" (Rev 2:15). Now, most of the Christian movement had become "organized" under the "control" of man. Those opposing the teachings of this Nicolaitane (conquer the laity) form of Christianity were put to death.
The Nicolaitane influence continued to grow in the church, causing more and more controversy and division. Peter's prophecy had come to pass (2 Peter 2:1) and one of those damnable heresies that Peter warned about was the teaching of the doctrine of the trinity - three person concept of the Godhead. The early church did not believe in three persons in the Godhead. They believed in the Father, the Son and the Holy Ghost - simply believing that each was a "dispensational manifestation" of ONE and the same God. But with organized religion came intellectual theologians, without Spiritual revelation. They took it upon themselves to take the understanding of the Word out of the hands of the Holy Ghost and place it in the hands of the clergy of the organized church. Until finally, during the dark ages, the organized antichrist church forbid the ordinary person to read the Scriptures, causing them to depend entirely on the clergy for spiritual guidance or rather, misguidance.
Still, after 1700 years no other doctrine is as "sacred" to "traditional" organized Christianity (both Roman Catholic and Protestant) as the doctrine of the trinity. To the "traditional" Christian teaching of the three person concept of the Godhead is a "precious jewel" in their Christian confession. Dare anyone, even God Himself, challenge the Scripturalness of it. Most professing Christians turn a blind eye and a deaf ear to the truth of where the trinity - three person concept of God originated. The tradition of the elders have made a false trinity doctrine the cornerstone of the Christian Faith thereby replacing the true cornerstone - Jesus Christ, the ONE God manifest in the flesh. For this they will answer to God.