In Modern Man in Search of a Soul, C.G. Jung discusses the importance of understanding mysticism and religion in helping a patient to heal and the dangers of reducing psychology to mere science:
Theology does not help those who are looking for the key, because theology demands faith, and faith cannot be made: it is in the truest sense a gift of grace. We moderns are faced with the necessity of rediscovering the life of the spirit; we must experience it anew for ourselves. It is the only way in which we can break the spell that binds us to the cycle of biological events.
My position on this question is the third point of difference between Freud’s views and my own. Because of it I am accused of mysticism. I do not, however, hold myself responsible for the fact that man has, everywhere and always, spontaneously developed religious forms of expression, and that the human psyche from time immemorial has been shot through with religious feelings and ideas. Whoever cannot see this aspect of the human psyche is blind, and whoever chooses to explain it away, or to “enlighten” it away, has no sense of reality. Or should we see in the father-complex which shows itself in all the members of the Freudian school, and in its founder as well, convincing evidence of any release worth mentioning from the inexorable family situation? This father-complex, fanatically defended with such stubbornness and over-sensitivity, is a cloak for religiosity misunderstood; it is a mysticism expressed in terms of biology and the family relation.
As for Freud’s idea of the “super-ego”, it is a furtive attempt to smuggle in his time-honoured image of Jehovah in the dress of psychological theory. When one does things like that, it is better to say so openly. For my part, I prefer to call things by the names under which they have always been known. The wheel of history must not be turned back, and man’s advance toward a spiritual life, which began with the primitive rites of initiation, must not be denied. It is permissible for science to divide its field of enquiry and to set up limited hypotheses, for science must work in that way; but the human psyche may not be parceled out. It is a whole which embraces consciousness, and is the mother of consciousness. Scientific thought, being only one of its functions, can never exhaust all the possibilities of life. The psychotherapist must not allow his vision to be coloured by the glasses of pathology; he must never allow himself to forget that the ailing mind is a human mind, and that, for all its ailments, it shares in the whole of the psychic life of man.
Excerpt from the Carl Jung ebook, Modern Man in Search of a Soul