The importance of relating with God for Spiritual Well-BeingTwenty years of research in spiritual health/well-being culminate in this thesis. My PhD (1998), University of Melbourne, presented a Four Domains Model of Spiritual Health/Well-Being. This formed the theoretical base for several spiritual well-being questionnaires, presented in my EdD ( 2009), University of Ballarat. The main instrument, Spiritual Health And Life-Orientation Measure (SHALOM), proposed a novel method of assessing quality of relationships which are posited as reflecting spiritual well-being.These relationships are of each person with themselves, others, the environment and/or with a Transcendent Other (God). Instead of just investigating lived experiences, SHALOM asks for two responses to each item. Each respondent's lived experience is compared with their stated ideals. Studies presented herein show that this double-response method, comparing ideal with actual, provides a statistically stronger measure of quality of relationships than lived experiences alone, thus spiritual well-being.Eighteen publications included in this thesis relate to studies of spiritual wellbeing in educational, healthcare and general community settings. A total of 52 studies, using SHALOM with 41686 people from 27 countries, have shown that, of the four sets of relationships measured by SHALOM, relating with God explains greatest variance in spiritual well-being, so is therefore most important.An international study with people involved with, as well as some opposed to, spirituality and religious education led to a generic form of SHALOM, in which the theistic words were replaced by 'Transcendent', with 19 alternatives provided from which to select preferred Transcendent, or none. This project revealed that relating with God, as Transcendent, provides greatest support for a person's relating with self and others, in contrast to help provided by non-theistic and non-religious Transcendents and not believing in Transcendents. This research implies that researchers need to investigate relationship with God in any study of spiritual well-being, whether or not it fits their personal worldview.