Adapted from a longer timeline of church history found in The New International Dictionary of Pentecostal and Charismatic Movements Eds. Stanley M. Burgess and Eduard M. VanderMaas (Zondervan, Grand Rapid, 2003) pg. 2869-2873

What is meant by the term “three waves” and where did it come from? Excerpt From Chapter 8 Pentecostalism: A Very Short Introduction By William K. Kay (Oxford University Press, New York. 2011)

The most sustained attempts to understand Pentecostalism on a large scale have come from David Barrett and his co-worker Todd Johnson. Barrett edited the first edition of the World Christian Encyclopaedia (published by Oxford University Press) in 1982 and summarized all the main statistics connected with world Christianity, both country by country and also by ecclesial megablocks: Roman Catholic, Protestant, Orthodox, non-white indigenous, Anglican, marginal Protestant, and Catholic (non-Roman). His monumental labours enabled him to place Christianity against the growth of the world population since the time of Christ and to make predictions from trends carried forward to the year 2000. He was able to show that in 1985 there were approximately 1.54 billion Christians, or 32.4% of the world’s population, and that these numbers were poised to grow.

In the re-presentation of these figures related specifically to Pentecostalism and published in The New International Dictionary of Pentecostal and Charismatic Movements (Zondervan, 2002), Barrett changed his categorization of groupings by viewing them as three historic waves of the Holy Spirit moving across the world. The first began in 1886 and produced the classical Pentecostal denominations which, by the year 2000, comprised 65 million people. The second wave, though it gained impetus in the 1960s, began in 1907 and comprised charismatics - those who spoke in tongues and believed in spiritual gifts but who remained in traditional denominations. These amounted to 175 million people. And, in the final wave, were a further 295 million who were made up of indigenous African Pentecostals, post-denominationalists, New Apostolics, and other apostolic networks. Altogether, he reached a grand total of 523 million, which he calculated amounted to 8.63% of the world’s population. As he pointed out, such a vast array of people generated massive human and financial resources. He counted 740 Pentecostal denominations and 6,530 non-Pentecostal denominations with large internal charismatic sections, and all these were dispersed among 9,000 ethnic or linguistic cultures.

Even the United Nations does not possess a better set of figures than Barrett. What he sees is three spiritual waves, each with its own separate characteristics. The classical Pentecostals are the most careful to define their doctrine and the most organized into denominational forms with mechanisms for establishing and propagating themselves. The charismatics live within traditional denominations, some of which are evangelical, and have in the past been the most educated but least strict about their exact Pentecostal beliefs. The third-wave churches are heterogeneous in organization and beliefs but frequently missional, authoritative, and radical. Each of the waves co-exists with the others, influences them, and grows at its own pace. The charismatics now outnumber the classical Pentecostals by about nine to one, and this has the effect of increasing the range of Pentecostal-style beliefs and practices - a diversity that may become wider when the profile of Christianity in China is fully revealed.