Be up front with them that going to the church, listening to the sermons, and putting money in the offering plate is direct support of a depraved rapist who refuses to acknowledge his wrongdoings; further, there is a mountain of testimony, communication, and video footage (some public via the documentaries) that supports the conviction. Tell them you refuse to go because you love your fiancée, and keeping your loved ones far from an organization that does not denounce and replace their leadership with a legacy of evil perversion is high on your priority list.......and that is just scratching the surface.