A variety of confluent streams created Pentecostalism. The movement owes much to Methodist, Pietist, and the Holiness movements that stretch from the 18th to 19th century. These movements shared a desire to deepen the experience of conversion by overcoming sin through a continual work of holy living. Articulating Christianity's appeal to the masses as a "religion of the heart" did not begin with John Wesley, but he certainly can be credited for founding one of Christianity's most enduring movements.
John Wesley (1703-1791) promoted Christian perfection as a model of holy living. What began as a reform movement within the Anglican Church became a global movement stressing grace, sanctification, and social reform. Of particular note was John and his brother Charles's trip to the colony of Georgia in 1735, where their desire to convert Native Americans ran into the realities of colonial and missions politics. On his way to Georgia, John was introduced to and became impressed by the steadfast faith displayed by Moravian missionaries traveling with him. This relationship would continue for the next several years even as Wesley failed at becoming a major force in the conversion of Native Americans and left to return to England. What did not disappoint him was the fervency and pietism of his Moravian friends.
German Pietism, especially that of the Moravians, stressed a faith life that sought to overcome sin. In Wesley's case, it was this emphasis on the victory over sin as well as the Pietist emphasis on the continuing miracles described in the New Testament that attracted him. Pietism especially focused on healing as a part of the life of every Christian, and linked this to the idea that sickness originated in sin. Therefore, if sin could be overcome, then health was part of the life that all Christians could claim for themselves. What Wesley, the Pietists, and later movements such as the Holiness movement all stressed was that living out the Christian life meant that one had to take on the life of Jesus, accepting the scorn as well as the victory that emanated from living a sacrificial life of rigorous practices (prayer, fasting, Bible reading, piety).
Another significant influence in the stream of Christian spirituality that eventually led to the development of Pentecostalism was the British Keswick movement. The Keswick or Higher Life movement began in England in the 1870s. Seeking to reinvigorate the Wesleyan notion of Christian perfection, Keswick proponents believed that there was an essential component to life after conversion, mainly that being "sanctified" or "filled with the Holy Spirit" was part of seeking a deeper faith. The movement was promoted on a variety of fronts, especially by William Boardman, who began holding meetings to promote the "Higher Life" in Keswick. Boardman brought in other influential people who began writing on the topic of Christian perfection and the Higher Life, and soon the movement began to influence many of the Methodist churches in England. The meetings began in 1875 and continue to this day.
Before there was an established Holiness movement (an offshoot of Methodism), there were several particular events that are now seen as precursors to Pentecostalism. It is worth noting them since they are both theologically and experientially significant to the discussion of the streams that influenced Pentecostalism.
In 1801 in Cane Ridge, Kentucky, Barton Stone, a preacher who had founded his own Restorationist movement with Alexander Campbell (later to be known as the Churches of Christ and Disciples of Christ movements among others), had a series of revival meetings stressing holy living and rededicating one's life to Jesus. These have been described as precursors to Pentecostal revivals more than a hundred years later. Between 20,000 and 40,000 people attended these meetings between 1801-1804. People fainted, began shaking, singing, and exhibiting other phenomena such as barking like animals.
The significance of these meetings is found in the idea that Holiness teachings advocating the eradication of sin seem to precede the outbreak of phenomena. With Pentecostalism's growth and maturation, these phenomena have been given theologically significant responses. In common parlance, fainting in a time of worship is called being "slain in the Spirit." Being overtaken by the Holy Spirit has been described as akin to shaking uncontrollably.