Speaking in tongues

===20th century===
{{Main|Azusa Street Revival}}
[[File:026 la times.gif|thumb|upright=1.25|Headline about the "Weird babel of tongues" and other behavior at Azusa Street, from a 1906 ''[[Los Angeles Times]]'' newspaper]]
During the 20th century, glossolalia primarily became associated with Pentecostalism and the later [[charismatic movement]]. Preachers in the [[Holiness Movement]] preachers [[Charles Parham]] and [[William J. Seymour|William Seymour]] are credited as co-founders of the movement. Parham and Seymour taught that "baptism of the Holy Spirit was not the blessing of sanctification but rather a [[third work of grace]] that was accompanied by the experience of tongues".<ref name="FahlbuschBromiley1999" /> It was Parham who formulated the doctrine of "initial evidence". After studying the Bible, Parham came to the conclusion that speaking in tongues was the Bible evidence that one had received the [[baptism with the Holy Spirit]].

In 1900, Parham opened [[Bethel Bible College]] in [[Topeka, Kansas]], America, where he taught initial evidence, a Charismatic belief about how to initiate the practice. During a service on 1 January 1901, a student named [[Agnes Ozman]] asked for prayer and the [[laying on of hands]] to specifically ask God to fill her with the [[Holy Spirit]]. She became the first of many students to experience glossolalia, in [[Millennium#Counting years|the first hours of the 20th century]]. Parham followed within the next few days. Parham called his new movement the [[Charles Fox Parham|apostolic faith]]. In 1905, he moved to Houston and opened a [[Bible school]] there. One of his students was William Seymour, an African-American preacher. In 1906, Seymour traveled to [[Los Angeles]] where his preaching ignited the [[Azusa Street Revival]]. This revival is considered the birth of the global Pentecostal movement. According to the first issue of William Seymour's newsletter, ''The Apostolic Faith'', from 1906:

{{blockquote|A [[Mohammedan]], a Soudanese by birth, a man who is an interpreter and speaks sixteen languages, came into the meetings at Azusa Street and the Lord gave him messages which none but himself could understand. He identified, interpreted and wrote a number of the languages.<ref>Square brackets indicate faded parts that are no longer readable.</ref>}}

Parham and his early followers believed that speaking in tongues was xenoglossia, and some followers traveled to foreign countries and tried to use the gift to share the Gospel with non-English-speaking people. From the time of the Azusa Street revival and among early participants in the Pentecostal movement, there were many accounts of individuals hearing their own languages spoken 'in tongues'. The majority of Pentecostals and Charismatics consider speaking in tongues to primarily be divine, or the "language of angels", rather than human languages.<ref>D. Swincer, ''Tongues: Genuine Biblical Languages: A Careful Construct of the Nature, Purpose, and Operation of the Gift of Tongues for the Church'' (2016) pp. 88–90 {{ISBN?}}</ref> In the years following the Azusa Street revival Pentecostals who went to the mission field found that they were unable to speak in the language of the local inhabitants at will when they spoke in tongues in strange lands.<ref>Faupel, D. William. ''Glossolalia as Foreign Language: An Investigation of the Twentieth-Century Pentecostal Claim''. {{cite web |url=http://wesley.nnu.edu/wesleyan_theology/theojrnl/31-35/31-1-05.htm |title=31-1-05 |access-date=2005-04-27 |url-status=dead |archive-url=https://web.archive.org/web/20050429071428/http://wesley.nnu.edu/wesleyan_theology/theojrnl/31-35/31-1-05.htm |archive-date=29 April 2005}}</ref>

The revival at Azusa Street lasted until around 1915. From it grew many new Pentecostal churches as people visited the services in Los Angeles and took their newfound beliefs to communities around the United States and abroad. During the 20th century, glossolalia became an important part of the identity of these religious groups. During the 1960s, the [[charismatic movement]] within the [[Mainline Protestantism|mainline Protestant]] churches and among [[Catholic Charismatic Movement|charismatic Roman Catholics]] adopted some Pentecostal beliefs, and the practice of glossolalia spread to other Christian denominations. The discussion regarding tongues has permeated many branches of Protestantism, particularly since the widespread charismatic movement in the 1960s. Many books have been published either defending<ref>Example: Christenson, Laurence, ''Speaking in tongues: and its significance for the church'', Minneapolis, MN : Dimension Books, 1968.{{ISBN?}}{{page needed|date=June 2020}}</ref> or attacking<ref>Example: Gromacki, Robert Glenn, ''The Modern Tongues Movement'', Nutley, NJ: Presbyterian and Reformed Publishing Co., 1973, {{ISBN|0875523048}} (Originally published 1967){{page needed|date=June 2020}}</ref> the practice.