Firstly, people were seeking the "gift of languages".  Among those committed to world evangelisation serious concerns arose over how the unreached millions were going to hear the gospel before the end. Several factors generated these concerns: The missions movement had spent considerable time and energy but the numbers of conversions of native peoples was alarmingly small; the premillennialists' gloomy assessment of the immediate future caused Christians in this movement to expect the condition of humankind to get worse before the imminent return of the Lord; and then when the arms race of the 1890s occurred and the end of the century was approaching, the Christian expectation of the end of the world was considerably heightened.
Widespread interest in the gifts of the Spirit convinced some that God was going to restore the gift of tongues (identifiable human languages) to the Church to equip them to preach the gospel in other countries, in preparation for the end. In 1895 the widely read Holiness author W. B. Godbey predicted: “[The “Gift of Language” is] destined to play a conspicuous part in the evangelization of the heathen world, amid the glorious prophetical fulfilment of the latter days. All missionaries in heathen lands should seek and expect this Gift to enable them to preach fluently in the vernacular tongue, at the same time not depreciating their own efforts.” 
Frank W. Sandford was another teacher who advocated the missionary use of tongues-speaking. He spread this teaching in his publication “Tongues of Fire” through which he endevoured to rapidly evangelise the world. He and others were praying and expected to receive the gift of “power and eloquence” for evangelism. This desire for the gift of languages set the stage for the revival of tongues speaking that occurred in the early 1900s.
Secondly, people were seeking a restoration of the "full" gospel. The Holiness movement sought to restore what it understood to be New Testament Christianity to the Church in the last days in preparation for Christ's return. This led to the movement reforming existing theology to develop what it saw to be the “full" gospel. Reflecting this desire, A. B. Simpson blended together four themes of Christ as Savior, Baptizer, Healer, and Coming King. In time this was described as the “full gospel” or “fourfold gospel.”  This change of theology set the stage for Pentecostalism.
"By the turn of the century, the Holiness movement had become preoccupied with the “Pentecostal reformation of Weslyan doctrine” and the four themes of the full gospel. In fact, when the Pentecostal movement began a few years later, only the priority given to the gift of tongues distinguished it theologically from Holiness beliefs." Thirdly, people were seeing spiritual experiences as “crisis” events. The Holiness movement taught that Christian spirituality involved seeking distinct experiences that occured as instant events. This in turn set the stage for the Pentecostal doctrine of Spirit baptism as a separate experience to conversion.
"Not only did such Holiness teachers emphasize conscious religious experiences, they tended to encourage persons to seek for them as “crisis” experiences that could be received in an instant of time through prayer and faith. By 1890 the Holiness movement began to think of religious experiences more in terms of crisis than in gradual categories. Thus the Fire-Baptized Holiness Church taught instant conversion through the new birth, instant sanctification as a second blessing, instant baptism in the Holy Ghost and fire, instant divine healing through prayer, and the instant premillennial second coming of Christ." Fourthly, there was a need for "evidence" of the second work. Benjamin Hardin Irwin was a radical Weslyan Holiness preacher who taught a third work of grace for power in Christian service. In 1895 he began teaching that the second work of grace initiated sanctification and the third brought baptism in the Spirit. This “third blessing” was called “the fire.” Irwin named his group the Fire-Baptized Holiness Church, beginning another movement that started new groups across America and Canada. This created the problem of needing evidence to distinguishing between those who had received the third blessing from those who had the second only. This problem was part of the reason why the mainstream Holiness Movement rejected his as the “third blessing heresy.”
This controversy laid an important foundation for Pentecostalism because it crystallised the movement's commitment to a two-stage work of the Spirit (which would be simpler to identify). It also highlighted the need to clarify what is the nature of the second work of grace (which would be empowerment, not sanctification). In addition, the Irwin heresy (as it was called) revealed the need for an evidence for the second work of grace. This again set the stage for Pentecostalism which provided that evidence. Irwin later joined the Pentecostal Movement.
To summarise, the historical situation at the turn of the nineteenth-century that encouraged the appearance of Pentecostalism was a widespread desire for the gift of languages for world evangelisation, the desire for a restoration of the “full gospel” involving Spirit-baptism as a post-conversion experience and the miraculous gifts such as healing, the emphasis on spiritual experiences as “crisis” events, and the theological necessity of an evidence to distinguish those having received subsequent works of the Spirit from those who had not.
But in order to understand the origin of Pentecostalism completely we also need to understand how early Pentecostal thinkers themselves interpreted the historical events surrounding their beginnings. Did they themselves understand their doctrine of tongues-speaking to be unique in church history? Did they interpret the events surrounding the beginning of the twentieth-century as the end-time restoration of the “Apostolic faith” in preparation for Christ's return? In the next article, we'll talk about how early Pentecostals viewed Pentecostalism.
How early Pentecostals saw themselves
(PART 3) Where Pentecostalism came from - The Holiness movement
Why Pentecostalism was successful
 Vinson Synan (Ph. D., University of Georgia), “Pentecostalism”, Evangelical Dictionary of Theology, 2nd Ed., Paternoster Press, 2001, p. 899.
 Gary B. McGee (Ph.D., Professor of Church History, Chair, Bible and Theology Department at Assemblies of God Theological Seminary), Systematic Theology, Chapter 1 “Historical Background”, Logion Press, 1995, p. 14-15.
 Ibid., p. 15.
 Ibid., p. 14-15.
 Ibid., p. 15-16.
 Vinson Synan (Ph. D., University of Georgia), “Pentecostalism,” Evangelical Dictionary of Theology, 2nd Ed., Paternoster Press, 2001, p. 900.
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