The passage to heaven or hell lies through the world of spirits, which is much like our own world. The newly dead are often unaware of their transition, and linger on, trying to gratify their carnal desires. Gradually they come to terms with their "true affections."

The central narrative in Egyptian mythology, Osiris' dismemberment and resurrection, is paralleled in shamanic initiation rituals. The Egyptian themes of the journey of the soul through the underworld and spiritual ascent through the stars can also be found in shamanic ritual. That Plato described a version of this stellar ascent too suggests a shared source.

There was a method to Jung's madness: active imagination. It, along with the transcendent function, are the two most important discoveries Jung made in the years leading up to World War One. They describe a method of consciously entering into a dialogue with the unconscious to trigger a vital shift in consciousness, brought about through the union of the conscious and unconscious minds. 

The evolution of consciousness isn't something that "happens to us," or at least it needn't be. Simply becoming aware of the creative power of our own minds can achieve remarkable results. -- an interview with the author of A Secret History of Consciousness.