By World War I, the Holiness movement, a Wesleyan renewal movement, had been around for a half-century and some of its groups were becoming institutionalized. Some of the more radical groups were promoting pacifism at the time of World War I.
Holiness Roots to Pentecostal Pacifism
Pentecostalism is a subgroup of the Holiness Movement born as the Holiness movement was maturing. From about 1906 to 1908 radical Holiness leaders were becoming Pentecostalized with the phenomenon of speaking in tongues, as authentication of the Baptism in the Spirit. This effectively began to divide the Holiness movement over the issue of speaking in tongues. This radical wing of the Holiness movement and Pentecostalism were still somewhat united at the time of World War I over pacifism.