“‘Eternal torment’ is the term used by Alma2 (Mosiah 27:29; Alma 36:12). … Alma2 … suffered ‘eternal torment’ he described as ‘bitter’ and ‘exquisite,’ filling his soul with ‘inexpressible horror’ (Alma 36:12–21). When he accepted Christ, repented, and pleaded for mercy, he was delivered from his suffering and experienced ‘joy,’ which he said was ‘as exceeding as was [his] pain’ (Alma 36:20–21).
“How something ‘endless,’ ‘eternal,’ and ‘never-ending’ can come to an end is explained in latter-day revelation (D&C 19:6–12). … When the demands of justice are met in harmony with the plan of redemption, ‘endless punishment’ and ‘eternal punishment,’ meaning ‘God’s punishment,’ ends—for ‘Endless’ and ‘Eternal’ are names of God” (Largey, Book of Mormon Reference Companion, 242).