Despite remarkable progress in genetics, neuroscience, and pharmacology, modern medicine still cannot explain or cure thousands of rare and refractory diseases, including numerous psychiatric, neurological, dermatological, metabolic, and oncological conditions that remain resistant to all conventional treatments. However, an accumulating body of documented clinical recovery cases, together with direct observation of the spiritual realm through the Dharma Eye of Dharma Master Jun Hong Lu and the systematic practice of the Guan Yin Citta Dharma Door, clearly demonstrates that human existence comprises both a physical body and an immortal soul. The majority of treatment-resistant illnesses stem from either partial loss or dissociation of the soul, or from occupation of the body by external souls (deceased humans or animals, i.e., spirits). This paper therefore presents rigorous, verifiable evidence for the objective existence of the soul and the spirit world; elucidates the precise karmic and spirit mechanisms behind many diseases currently classified as “incurable” by modern medicine; and demonstrates that the Five Golden Buddhist Practices of Guan Yin Citta Dharma Door-making great vows, reciting Buddhist scriptures, performing life liberation, reading Buddhism in Plain Terms, and repenting of wrongdoings and refraining from doing them-provide a reproducible, effective pathway to partial or complete recovery. All these extraordinary outcomes rest upon the recognition of the soul’s existence. Accordingly, Buddhism is not merely a belief system, but the ultimate science of life, health, and the true nature of consciousness.