The Indian Shaker Church shares its name with the celibate New England sect but has no other connection to it, a distinct new religious movement Squaxin Island prophet John Slocum founded in 1881 on the shore of Puget Sound after an experience his followers describe as a return from death. Slocum, by his own and his community's account, had died and revived during his own wake, reporting that he had been told in the afterlife to abandon old ways and begin a new form of worship, and the church that grew from that experience took its defining practice two years later, in 1883, when Slocum's wife Mary was overcome by an uncontrollable trembling while praying over her ill husband, a shaking his recovery afterward led the community to treat as a form of divine healing power. The church spread among coastal Salish communities through the following decades, blending elements of Christian worship with Native ceremonial practice on the tribe's own terms rather than through missionary imposition, and it formally incorporated in Washington in 1910 after already gaining recognition in Oregon in 1907, a legal status it still holds.
That syncretic tradition sits alongside a Puget Sound region with among the highest rates of religious non affiliation of any metropolitan area in the country, and alongside Scandinavian Lutheran congregations founded by the region's fishing and logging communities and newer Sikh, Hindu and Buddhist communities brought by more recent immigration. Evangelical Protestant identification leads the state at twenty three percent of adults, per Pew's 2023-24 study.