We report the case of a female in her 40s diagnosed with depression. She was raised by an eccentric father, suspected of having pervasive developmental disorder, and a dominant mother. After graduating from high school, she worked as a clerk in a company for twenty years or so; however, a change in her work environment made her fall into a depressive state. Her worsening depression caused her impulsive resignation and disappearance for about four months. She spent the duration of her disappearance traveling the country, with no dissociative episodes. After returning, she received treatment for depression as an inpatient for about four months. During the first month of hospitalization, she mainly complained of a depressive mood and anxiety over the prognosis of her disorder, while she made scarcely any progress in introspection. In the second month, she gradually advanced with introspective work, but, as her introspection progressed, her depressive mood became aggravated. The therapist avoided intervention to modify her cognition, and told her the following: "it is better not to persist in managing your depressive mood itself because curing depression does not mean resolving the superficial depressive mood, but to achieve a condition not directly influenced by mood." Then, at the beginning of the third month, she became aware of "the presence of God" and, at the same time, her depressive mood greatly improved. She extended her sympathy to her mother with her unfortunate life history, and expected her mother to change as she herself had experienced, but, disappointed by her mother, she experienced anxiety attacks and came to realize her own internal rage against significant persons in her life including her mother. After "the Great being" experience, she, who had formerly attended Christian church for a short time, started to read the Bible, but she still hesitated about committing herself to "religious following." One day during the last month of hospitalization, as she prayed to God for healing when she read a part in the Bible about a woman suffering from a hemorrhage for twelve years who touched the hem of Jesus' garment and was healed immediately (Matthew 9:20-22 and Luke 8:43-48), the patient suddenly experienced "the salvation of God" and realized what trust really meant. Through the experience, her clinical problems became totally cured, and the therapy concluded with her discharge from hospital. Several months later, she sent the therapist a letter including the following message: "I am grateful to the Lord for salvation from anxiety and irritation, but to the therapist for helping me realize it." This clinical course can be understood based on the patient's clinical problems (e.g., despair, anxiety, and depression), arising from the breakdown of her efforts to maintain stability by founding her psychological base on her feelings of omnipotence, avoiding facing her internal negative psychological factors (e.g., rage), and these were automatically resolved when her psychological base was switched to the transcendent level through "the Great being" experience and "the salvation of God." Such a sudden, marked improvement resembles what Miller and C'de Baca reported as "quantum change," of which the characteristics are vividness, surprise, benevolence, and permanence. The therapist paid attention to maintain a constant psychological distance from the patient, not persisting in modifying her cognition, with the transcendent level being the basis for the entire therapy. This stance of the therapist itself was considered to prompt her transcendence and bring about her eventual cure. This clinical course seemed to be highly suggestive of a psychotherapeutic mechanism, indicating the close relationship between the transcendent level and basic trust.