The Pentecostal movement includes a large number of denominations, independent churches, and para-church organizations that emphasize the work of the Holy Spirit in the lives of Christian believers. It emerged first in North America at the beginning of the 20th century, when members of the Wesleyan Holiness Movement began to speak in tongues and identified it as the "Bible Evidence" that they had been baptized in the Holy Spirit (Acts 1:8, 2:1-4). This baptism in the Spirit was said to provide power for living an "apostolic" life and engaging in an "apostolic" ministry that included the charisms of 1 Corinthians 12:8-10. The movement has gone by such self-designations as "Apostolic Faith," "Full Gospel," "Latter Rain," and "Pentecostal". One of the first and most important centres of activity to identify itself as "Pentecostal," emerged under the direction of an African-American pastor, William Joseph Seymour, and the Apostolic Faith Mission at 312 Azusa Street in Los Angeles, in April 1906. Within 18 months of its beginning, the "Azusa Street" Mission had sent out scores of evangelists who crisscrossed North America, and missionaries who ministered in Europe, the Middle East, Africa, Asia, and Mexico.
The earliest Pentecostals drew from their Methodist and Wesleyan Holiness roots, describing their entrance into the fullness of Christian life in three stages: conversion, sanctification, and baptism in the Spirit. Each of these stages was often understood as a separate, datable, "crisis" experience. Other Pentecostals, from the Reformed tradition or touched by the Keswick teachings on the Higher Christian Life, came to view sanctification not as a crisis experience, but as an ongoing quest. This debate resulted in the first major schism among early Pentecostals. Groups such as the Church of God in Christ, the Church of God (Cleveland, TN), and the International Pentecostal Holiness Church continue to teach the former position, known as "Holiness". Groups such as the Assemblies of God and the International Church of the Foursquare Gospel hold the latter position, called "Finished Work".
A second major schism developed between 1907 and 1916, in discussions over the "apostolic" baptismal formula. Most Pentecostals argued for the classic Trinitarian formula, while others contended for the formula "in the Name of Jesus Christ" recorded in Acts (cf. Acts 2:38). By 1916 a new group of churches known as "Oneness" or "Jesus' Name" churches had formed. Among them are the Pentecostal Assemblies of the World and the United Pentecostal Church. Many of these groups ultimately embraced an understanding of the Godhead in terms that border on a modal understanding.
All three segments of Pentecostalism, "Holiness", "Finished Work" and "Oneness" believe in the imminent return of Jesus Christ, and therefore are highly evangelistic and missionary driven. As a result, Pentecostalism is today found in all the regions of the world, and is still growing. It is the largest non-Catholic Christian presence in Latin America. It has grown enormously throughout Africa, often giving rise to African Independent or Indigenous churches. In Asia, Pentecostalism is strong in places like the Philippines, Korea, India, and among the majority of house churches in China. The largest Pentecostal congregations in the world are found in Seoul and Surabaya. At the time of the beginnings of Pentecostalism, several autochthonous Pentecostal churches emerged in Chile (1910) and elsewhere in Latin America that were not directly touched by North American missionary efforts. It is these churches that have been most open to the ecumenical movement. Some of them became members of the WCC in the 1960s, and a good number have joined the Latin American Council of Churches after it was formed in 1982.
The majority of Pentecostal churches have chosen not to participate in any ecumenical organization. This comes, in part, because of their restorationist perspective on the history of the church that views existing churches as having fallen away from God's intentions through compromise and sin. Another reason is the way so many existing churches have marginalized and rejected the Pentecostals when they attempted to share their testimonies of what God had done in their lives. As a result, sectarian thinking has dominated much of the movement, which in many cases developed an eschatological position that feared ecumenical contact. In 1947, Pentecostals representing all but the Oneness groups gathered in Zurich, Switzerland for a Pentecostal world conference. Many leaders hoped to establish an organization for Pentecostals similar to the WCC that was then in formation. They were unable to do so because of the strongly congregational-centred Pentecostals of Scandinavia and Brazil. Since that time, Pentecostal leaders have gathered in Pentecostal world conferences where a small presidium has discussed items of mutual interest and concern. In 2004 the PWC formally took the name Pentecostal World Fellowship.
For the most part of the 20th century, Pentecostals have tended to identify with the Evangelical movement, and to join Evangelical structures. More recently, Pentecostal fellowships, federations or councils have emerged in a number of national and some regional situations. Pentecostal scholars have undertaken to build a body of Pentecostal theology.
Pentecostalism has been able to meet the needs of many on the margins of society and church. It has been effective in bringing people into a personal relationship with God through Jesus Christ, in the power of the Holy Spirit. It encourages its members to share their personal testimonies with others, to live their lives with an eye to "holiness", to embrace good works as part of the "Spirit-filled" life, to be open to the sovereign movement of the Holy Spirit through charisms, signs and wonders, and to support the work of the church through regular tithing. In recent years, some classical Pentecostal groups have begun to downplay the role of speaking in tongues as evidence of baptism in the Spirit, though they continue to value it as a legitimate charism of the Spirit. Some Pentecostal churches have embraced what is called a "prosperity theology", proclaiming that God wills both the spiritual and physical (including material) well-being of God's people. Churches such as the Universal Church of the Kingdom of God and the Pentecostal Church God Is Love that emerged in the 1980s in Brazil are controversial even among other Pentecostal churches, for the extent to which they emphasize this teaching.
The emergence of the National Association of Evangelicals in the USA and the World Evangelical Fellowship (now Alliance) in the 1940s, the testimony of the Latin American Pentecostal churches that joined the WCC, and especially the pioneering work of Pentecostal David du Plessis, have created a Pentecostal openness to limited ecumenical contact. Since 1972, Pentecostals have been in dialogue with the Pontifical Council for Promoting Christian Unity of the Catholic Church. Since 1993, they have been represented at the annual meeting of the Secretaries of Christian World Communions. An international dialogue was established between Pentecostals and the World Alliance of Reformed Churches in 1995, and another between Pentecostals and the WCC, through the Joint Consultative Group authorized at the Harare assembly in 1998. A new dialogue has been established with members from the Lutheran World Federation in 2005.
Groups that participate in the Charismatic Renewal and have maintained membership in their historic denominations have often formed positive relationships with the older classical Pentecostal churches.
Similarly, churches of the so-called "Third Wave" (largely charismatic groups like the Vineyard) and many "New Apostolic" groups are related to classical Pentecostalism. They all share many points of theology and experience. According to the World Christian Database, classical Pentecostals number 78 million, Charismatics 192 million and Neo-charismatics 318 million.