Like other forms of evangelical Protestantism, Pentecostalism adheres to the inerrancy of the Bible and the necessity of accepting Jesus Christ as personal Lord and Savior. It is distinguished by belief in the baptism in the Holy Spirit that enables a Christian to live a Spirit-filled and empowered life. This empowerment includes the use of spiritual gifts such as speaking in tongues and divine healing—two other defining characteristics of Pentecostalism. Because of their commitment to biblical authority, spiritual gifts, and the miraculous, Pentecostals tend to see their movement as reflecting the same kind of spiritual power and teachings that were found in the Apostolic Age of the early church. For this reason, some Pentecostals also use the term Apostolic or Full Gospel to describe their movement.
Pentecostalism emerged in the early 20th century among radical adherents of the Holiness movement who were energized by revivalism and expectation for the imminent Second Coming of Christ. Believing that they were living in the end times, they expected God to spiritually renew the Christian Church thereby bringing to pass the restoration of spiritual gifts and the evangelization of the world. In 1900, Charles Parham, an American evangelist and faith healer, began teaching that speaking in tongues was the Bible evidence of Spirit baptism and along with William J. Seymour, a Wesleyan-Holiness preacher, he taught that this was the third work of grace. The three-year-long Azusa Street Revival, founded and led by Seymour in Los Angeles, California, resulted in the spread of Pentecostalism throughout the United States and the rest of the world as visitors carried the Pentecostal experience back to their home churches or felt called to the mission field. While virtually all Pentecostal denominations trace their origins to Azusa Street, the movement has experienced a variety of divisions and controversies. An early dispute centered on challenges to the doctrine of the Trinity. As a result, the Pentecostal movement is divided between trinitarian and non-trinitarian branches, resulting in the emergence of Oneness Pentecostals.
Comprising over 700 denominations and a large number of independent churches, there is no central authority governing Pentecostalism; however, many denominations are affiliated with the Pentecostal World Fellowship. There are over 279 million Pentecostals worldwide, and the movement is growing in many parts of the world, especially the global South. Since the 1960s, Pentecostalism has increasingly gained acceptance from other Christian traditions, and Pentecostal beliefs concerning Spirit baptism and spiritual gifts have been embraced by non-Pentecostal Christians in Protestant and Catholic churches through the Charismatic Movement. Together, Pentecostal and Charismatic Christianity numbers over 500 million adherents.
Pentecostalism is an evangelical faith, emphasizing the reliability of the Bible and the need for the transformation of an individual's life through faith in Jesus. Like other evangelicals, Pentecostals generally adhere to the Bible's divine inspiration and inerrancy—the belief that the Bible, in the original manuscripts in which it was written, is infallible. Pentecostals emphasize the teaching of the "full gospel" or "foursquare gospel". The term foursquare refers to the four fundamental beliefs of Pentecostalism: Jesus saves according to John 3:16; baptizes with the Holy Spirit according to Acts 2:4; heals bodily according to James 5:15; and is coming again to receive those who are saved according to 1 Thessalonians 4:16–17.
The central belief of classical Pentecostalism is that through the death, burial, and resurrection of Jesus Christ, sins can be forgiven and humanity reconciled with God. This is the Gospel or "good news". The fundamental requirement of Pentecostalism is that one be born again. The new birth is received by the grace of God through faith in Christ as Lord and Savior. In being born again, the believer is regenerated, justified, adopted into the family of God, and the Holy Spirit's work of sanctification is initiated.
Classical Pentecostal soteriology is generally Arminian rather than Calvinist. The security of the believer is a doctrine held within Pentecostalism; nevertheless, this security is conditional upon continual faith and repentance. Pentecostals believe in both a literal heaven and hell, the former for those who have accepted God's gift of salvation and the latter for those who have rejected it.
For most Pentecostals there is no other requirement to receive salvation. Baptism with the Holy Spirit and speaking in tongues are not generally required, though Pentecostal converts are usually encouraged to seek these experiences. A notable exception is Jesus' Name Pentecostalism, most adherents of which believe both water baptism and Spirit baptism are integral components of salvation.