Lynn A. Thompson, President of the Priesthood of the Apostolic United Brethren, the largest Mormon fundamentalist religion, quietly passed away this week on October 5, 2021. "Mormon fundamentalist religion" is a term used by both early leaders of the movement and leaders within the LDS Church to differentiate themselves from those who continued the controversial marital practice. According to the Apostolic United Brethren, they were charged with continuing the "fundamentals" of the faith -- namely polygamy -- after the LDS Church essentially brought an end to the practice in 1904.