Some define Pentecostalism strictly on a doctrinal basis. The most commonly accepted doctrinal definition is that Pentecostals are those who hold to glossolalia as the "initial physical evidence" of Spirit Baptism. The problem is that not all within classical Pentecostalism are comfortable with that definition. Robert M. Anderson, defines Pentecostals as "the groups, by whatever name they may use, whose origins can be traced to that revival [Azusa]"; Vision of the Disinherited, p. 4. Both definitions challenge Charles Conn's claim. First, the evidence is weak that the Church of God believed that glossolalia was the biblical evidence of Spirit Baptism, and that this baptism was for all believers, until after January, 1908. Secondly, using Robert Anderson's definition, the oldest Pentecostal denominations would be Apostolic Faith (Baxter Springs, Kans.), Apostolic Faith Mission (Portland, Ore.), The Church of God in Christ, and The Pentecostal Holiness Church. All of these denominations can trace their origins to Azusa Street as early as 1906. (from Robert Horton's article "The Holiness Connection" Lee College, Cleveland, Tenn. March 1996)

the principles and practices of Pentecostal religious groups; characterized by religious excitement and talking in tongues

The doctrines and practices of Pentecostal religious bodies; especially, religious excitement or emotionalism accompanied by ecstatic utterances interpreted as the gift of tongues ( WTNID, p. 1673)

a movement originating in early 20th century America which emphasizes the so-called Baptism in the Holy Spirit with the consequent charismatic gifts of speaking in tongues, faith-healing, and prophesying. Pentecostal denominations comprise perhaps the fastest growing branch of religion in the world today. (see Charismatic movement)

The Pentecostal movement within Evangelical Christianity places special emphasis on the direct personal experience of God through the baptism of the Holy Spirit, as shown in the Biblical account of the Day of Pentecost. Pentecostalism is similar to the Charismatic movement, but developed earlier and separated from the mainstream church. Charismatic Christians, at least in the early days of the movement, tended to remain in their respective denominations.