Jung prefaces the book with a section called Lectori Benevolo. He starts this section with this, which lays the groundwork for the rest of the book:
…For, in what follows, I shall speak of the venerable objects of religious belief. Whoever talks of such matters inevitably runs the risk of being torn to pieces by the two parties who are in moral conflict about those very things. This conflict is due to the strange supposition that a thing is true only if it presents itself as a physical fact…”Physical” is not the only criterion: there are also psychic truths which can neither be explained nor proved nor contested in any physical way. (LB, 553)
It is interesting to me that we still see this battle between two camps: literalists who claim that we can’t have faith UNLESS it is backed up by physical facts; and atheists who claim that we can’t have faith BECAUSE it cannot be backed up by physical facts. I would not presume to think these are the two camps Jung had in mind, but it is something I see today. Jung continues to describe the psychic nature as autonomous of the physical, and thus of religious experience and language arising out of transpersonal, unconscious processes. These resultant religious statements…
are filtered through the medium of human consciousness…That is why whenever we speak of religious contents we move in a world of images that point to something ineffable. We do not know how clear or unclear these images, metaphors, and concepts are in respect of their transcendental object. If, for instance, we say “God”, we give expression to an image or verbal concept which has undergone many changes in the course of time. We are, however, unable to say with any degree of certainty…whether these changes affect only the images and concepts, or the Unspeakable itself…There is no doubt that there is something behind these images that transcends consciousness…(LB, 555).