Henry
A little history of the UPCI:
There was only one church with the twelve apostles and the apostle Paul.
Various groups began to splinter off (such as Judaizers, Nicolaitans, seen in Revelation 2,3). One such splinter group was the Catholics who began to appear around c.120 AD, teaching that Jesus was a separate divine Person from God the Father.
The Catholic church gained supremacy over other Christian groups (including those who remained faithful to apostolic teaching) between 250-325 AD). In 313 AD-325 AD they became the state (official) church of the Roman empire, and began to persecute other Christian groups. Through the Roman emperors and the successors (the empire of Charlemagne in western Europe and the Byzantine empire in eastern Europe) the Catholics remained in power as the favored state religion until the German princes began to back Martin Luther and other nation state rulers began to back Protestant groups following the Rennaissance in Europe.
But apostolic groups continued to exist down through the centuries, especially in eastern Europe (although the favored Catholic, and later Protestant groups-both followers of the trinity teaching-persecuted and harrassed apostolic groups, calling them heretics and executing those who disagreed with them).
The apostolic groups, who continued to preach Acts 2.38, were nearly exterminated in the Old World by the end of the nineteenth century (1890's) and in the early beginning of the twentieth century.
That is why it is significant that in 1900 over in America, God poured out His Spirit in Topeka KS (News Year's eve 1901) when Agnes Ozman, Rev. Charles Parham, and his students began receiving the baptism of the Holy Ghost.
God dealt with Brother Parham about being baptized in the Name of Jesus Christ
In 1913 at the Arroyo Seco, CA Camp Meeting, God showed to Rev. R.E. McAlister
the importance of the Name of Jesus Christ in water baptism and he preached that no one was baptized in the titles Father, Son and Holy Ghost in the New Testament, but rather in the Name of Jesus Christ (McAlister was to later renounce his teaching).
The revelation of this great truth hit John Schaepe in the camp who ran through the camp excitedly proclaiming this great truth. It affected Frank Ewart (he has books that can be purchased at Hazelwood headquarters). Frank Ewart and Glenn Cook both baptized one another in the Name of Jesus Christ.
It was Evangelist Glenn Cook who baptized Elder G.T. Haywood of Indianapolis in the Name of Jesus Christ. All of these men had received the baptism of the Holy Ghost, speaking in tongues. God was restoring full salvation in the western world so that the apostolic message could continue down through the centuries as it has.
These men, for the most part, who had joined already the organization called the Assemblies of God (which believed in the baptism of the Holy Ghost, but were trinitarian in their theology) were ostracized and effectively forced out of the Assemblies of God in 1916 at a conference in St Louis.
The men who were forced out of the Assemblies of God because of their belief in the Name of Jesus in water baptism formed some smaller organizations through the 1920's and 1930's. It is too complicated to go into here.
One organization, the PMA (Pentecostal Ministeral Alliance) later became the Pentecostal Church Incorporated. Another organization, the Pentecostal Assemblies of the World (PAW) became a largely Black Pentecostal Jesus Name body.
Two prominent oneness organizations emerged: the Pentecostal Assemblies of Jesus Christ (PAJC) and the Pentecostal Church Incorporated (PCI). They finally merged together in 1945 at St Louis to form the United Pentecostal Church.
God bless