The separation between spiritual environments is NOT enforced by God or God’s avenging angels or any other “authority” wielding an arbitrary set of religious dogmas! Each environment is exclusively the result of the thoughts and attitudes of the spirits who reside within them. The spiritual planes are maintained by natural spiritual laws. Each soul attains a particular spiritual buoyancy during its life and naturally gravitates to the level where it belongs. Some of the laws pertaining to the spiritual world are discussed in chapter 8, however, for now, just understand that souls attain a spiritual level perfectly matched to their own spiritual attributes. As an example, take spiritual vision.
Spirits who gravitate to the lower levels can see spirits who occupy their own plane, but cannot see spirits who come from the higher planes because of the observing spirits’ lower vibrational energy state (See spiritual frequencies in chapter 8). They are also incapable of seeing, or even sensing the planes above them. Those who have gravitated to the upper levels by virtue of their spiritual buoyancy have a higher vibrational energy and can see the spirits, not only on their own level, but also on the lower ones as well. However, they only venture into the darker and uninviting lower levels as missionaries to help the inmates who are ready to progress toward a more spiritually elevated state. It isn’t especially easy or comfortable for an advanced spirit to descend into a lower realm because in order to tolerate the conditions there, and even to be seen, heard and otherwise sensed by the lower spirits, they have to reduce their spiritual frequency which is not an easy task, and requires some special skills.
If a lower spirit manages to enter a higher plane, it would find the conditions there entirely intolerable. Once again, Swedenborg sheds light on this point:
“One ascending from a lower heaven is seized with a distress even to anguish, and is unable to see those who are there, still less to talk with them; while one descending from a higher heaven is deprived of his wisdom, stammers in his speech, and is in despair.”