Theosis re-considered. The dynamic nature of salvation: Gregory of Nyssa's 'stages of mystical ascent' in the 'Life of Macrina' re-visited through the biography of Machig Labdron and the Tibetan Vajrayana tradition of chod

The purpose of this dissertation is the recovery of the Eastern Orthodox Christian notion of theosis (deification) for all Christians across denominational and doctrinal boundaries, and its fresh re-appropriation in salvation theory and spiritual practice by theologians, ecclesiasts and laity alike. I will argue that theosis as a soteriological doctrine sums up the entire process and designates the final fruit of the Christian contemplative and liturgical praxis and life. Theosis is the living potentiality within each individual to transform oneself and the human condition of suffering, disease, decay and death into a life of bliss and happiness.;The concept of Buddhahood within a Tibetan Buddhist practice-oriented framework provides a lens through which I will revive and interpret theosis anew while showing it to be a dynamic process of individual spiritual ascension and communal realization of human-divine "inter-being" with significant ethical implications. The term theosis is not redefined by way of Buddhism, but its dynamic character and immanent existential and eschatological meaning are revealed by aid of a comparison with and an insight of the Tibetan Vajrayana Buddhist tradition. The goal is---through analogy between the Buddhist path of spiritual transformation and the Christian path---to revive, highlight and further Christ-like virtues, praxis and embodiment amongst Christians.;The methods used in this dissertation are historical, systematic, and comparative. A brief historical account of the philosophical and Scriptural background of the term theosis introduces its development in the thought of the Greek Fathers of the Church. The Life of Macrina is located systematically in the larger context of Gregory's corpus of ascetical writings. Close textual exegesis (primarily from translations) illustrate the stages of Macrina's "mystical" ascent and process of deification, adoption of the Christ image, and union with God.;Specific phenomenological and doctrinal comparisons between two hagiographical texts of the Christian and Buddhist traditions, their heroines Macrina and Machig, and their practices, illustrate the similarities and differences between theosis and Buddhahood. Finally, the analysis of the Life of Macrina through the Buddhist lens reflects on the soteriological, ethical and existential importance of theosis for all Christian praxis and life.