The Reverends Beatrice Gaulton-Bishop and John and Doris Horning founded the International Spiritualist Alliance of New Westminster, British Columbia in 1959. On September 25th of that year the ISA was incorporated as a church under the Society Act, with all rights and privileges, including the right to solemnize marriages. The ISA is a federally registered charity with the authority to issue tax-deductible receipts.
Initially, the primary objectives were to hold development circles and to train ministers in the spiritualist philosophy, which has a core belief that death is the gateway to a greater expression of life. They began with a small group of people who met in their homes.
The ISA grew, and in 1979 a permanent home for the Sunday services, Wednesday evening speakers, and workshops for mediums was established in a location on 8th Street near Royal Avenue in New Westminster. Since 2006 we have been upstairs at 317 Columbia Street, New Westminster. In 2009 the ISA celebrated its 50th anniversary.
Over the years, with the demise of many of the original international groups with which the ISA had been affiliated, in October 2017 the membership voted to change the name to The Spiritualist Alliance Society.