This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
In October 1916, the Assemblies of God, founded only two years earlier at Hot Springs, Arkansas, held its fourth General Council in St Louis, Missouri. The young fellowship had already developed a serious internal division: a minority within it had begun teaching baptism in the name of Jesus alone, rejecting the traditional Trinitarian formula and the doctrine of the Trinity itself outright.
The 1916 council responded directly to that division. It adopted a Statement of Fundamental Truths affirming Trinitarian doctrine as the fellowship's own official position, requiring ministers to sign on to a doctrine the dissenting minority had explicitly rejected.
The cost of that statement was immediate and large. Roughly a third of the Assemblies of God's ministers, the Oneness believers among them, withdrew from the fellowship rather than sign the new Trinitarian statement, refusing to affirm a doctrine they did not hold.
What the October 1916 council changed for Pentecostalism's spread was a permanent split into two distinct branches. Ministers who withdrew rather than sign the Trinitarian statement went on to found what became known as Oneness Pentecostalism, a separate branch of the movement that traces its own founding directly to the doctrine the General Council had just made mandatory.