Mormon Doctrine, pg. 349; “That part of the spirit world inhabited by wicked spirits who are awaiting the eventual day of their resurrection is called hell. Between their death and resurrection, these souls of the wicked are cast out into outer darkness, into the gloomy depression of sheol, into the hades of waiting wicked spirits, into hell. There they suffer the torments of the damned…Hell will have an end. Viewing future events, John saw that “death and hell delivered up the dead which were in them: and they were judged every man according to their works.” (Rev. 20:13.)…After their resurrection, the great majority of those who have suffered in hell will pass into the telestial kingdom; the balance, cursed as sons of perdition, will be consigned to partake of endless wo with the devil and his angels…”
Revelation 20:12-15; “And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works. 13 And the sea gave up the dead which were in it; and death and hell delivered up the dead which were in them: and they were judged every man according to their works. 14 And death and hell were cast into the lake of fire. This is the second death. 15 And whosoever was not found written in the book of life was cast into the lake of fire.”
They’re in for a rude awakening if they think their torment will have an end.