A theoretical framework of existential coherence is presented, explaining how health, quality of life (QOL), and the ability to function were originally created and developed to rehabilitate human life from an existential perspective. The theory is inspired by the work of Aaron Antonovsky and explains our surprising recent empirical findings -- that QOL, health, and ability primarily are determined by our consciousness. The theory is a matrix of nine key elements in five layers: (1) coherence; (2) purpose and talent; (3) consciousness, love, and physicality/sexuality; (4) light and joy; and (5) QOL/meaning of life. The layer above causes the layer below, with the layer of QOL again feeding the fundamental layer of coherence. The model holds the person responsible for his or her own degree of reality, happiness, and being present. The model implies that when a person takes responsibility in all nine "dimensions" of life, he or she can improve and develop health, the ability to function, all aspects of QOL, and the meaning of life. The theory of existential coherence integrates a wide range of QOL theories from Jung and Maslow to Frankl and Wilber. It is a nine-ray theory in accordance with Gurjieff's enneagram and the old Indian chakra system. It can be used in the holistic medical clinic and in existential coaching. Love is in the center of the model and rehabilitation of love in its broadest sense is, accordingly, the essence of holistic medicine. To know yourself, your purpose of life (life mission) and talents, and taking these into full use and becoming coherent with life inside and reality outside is what human life is essentially about. The new model has been developed to integrate the existing knowledge in the complex field of holistic medicine. Its strength is that it empowers the holistic physician to treat the patient with even severe diseases and can also be used for existential rehabilitation, holistic psychiatry, and sexology. Its major weakness is that it turns holistic medicine more into an art than into a science because the physician must master intent, which is a poorly understood dimension of existence.