The so-called "Third Wave" in Pentecostal Christianity, observed during the second half of the 20th century, describes a shift in theological conviction by non-Pentecostal scholars toward recognizing the existence and operation of certain expressions of the faith, like speaking in tongues, that were traditionally categorized as Pentecostal.
The term "third wave" (as well as "first wave" and "second wave") were named by scholar, C. Peter Wagner, a long-time professor at Fuller Theological Seminary, who is also known for his work in spiritual warfare and missiology.
For context it is is important to know that Pentecostalism is an expression of orthodox Christianity, which emphasizes the Holy Spirit in belief and practice. While the movement, and its various denominations, is relatively new, it has become one of the largest and fastest-growing branches of the Christian religion.
The Three Waves of Pentecostalism
According to Wagner, the “First Wave” was the birth of the modern Pentecostal movement under Charles Parham, W.J. Seymour, and the Azusa Street Revival. The Los Angeles-based Asuza Street Revival produced nationwide growth of the Pentecostal movement.
The “Second Wave” was the charismatic movement of the 1960’s, which saw Pentecostal experiences occur in non-Pentecostal churches. This phenomenon is sometimes called Neo-Pentecostalism and also the Charismatic Movement.
The “Third Wave” refers to non-Pentecostal Christians who believe in the miraculous gifts and works of God, yet don't regard baptism of the Holy Spirit as a second work of grace. Perhaps the most well-known group ascribing to the “Third Wave” is the Vineyard movement.
As noted above, C. Peter Wagner is a former professor of Church Growth at Fuller Theological Seminary. He is well-known for books on spiritual warfare, including "Confronting the Powers" and "Engaging the Enemy."
He advocates strategic engagement in spiritual warfare, including confronting territorial demons and calling demons by their name. He is also known for advocating the destruction of the statues of Catholic saints, which he teaches are idols representing spiritual darkness.