What was the Jesus Only movement within Pentecostalism?

The "Jesus Only" movement, also known as the Oneness or Apostolic movement, is a theological branch within Pentecostalism that rejects the traditional doctrine of the Trinity in favor of the belief that Jesus is the sole person in the Godhead.12

The movement emerged around 1913 after R.E. McAlister began teaching that water baptism should be performed exclusively "in the name of Jesus Christ," citing the Acts of the Apostles (2:38), rather than using the traditional Trinitarian formula ("in the name of the Father, the Son and the Holy Spirit") found in the Gospel According to Matthew. Following an emotional testimony by John G. Scheppe regarding the power of Jesus' name, the teaching gained significant traction.12

This theological shift caused a major schism within Pentecostalism, as Trinitarian groups labeled the movement a heresy. Notable denominations that adhere to this theology include the United Pentecostal Church International and the Pentecostal Assemblies of the World, Inc..123