Another group with no idea what heaven is like was also making an effort to get in. They were told that unless they possessed a faith inspired by love, entering heaven was as dangerous as walking through fire; but they still insisted. On reaching the “front entryway”—the lower realm of angelic spirits—they received such a blow that they went tearing off in the opposite direction as fast as they could go. From this they learned how much danger there was in merely approaching heaven before the Lord had prepared them to feel the emotions that come with faith.
A certain spirit who in bodily life had considered adultery perfectly harmless was also allowed to cross heaven’s first threshold, since that was what he wanted. On arriving there, he began to suffer and to smell his own corpselike stench. These sensations grew until he could no longer stand them. If he had gone any farther, it seemed to him, he would have been destroyed.
Consequently he was banished from there to the underground realm. He felt angry that crossing heaven’s first threshold meant undergoing such tortures, since he was entering an environment opposed to adultery. He is one of the unfortunate ones.
from Secrets of Heaven, Volume 1, Sections 538, 539