The other names for spirit prison are “hell” and “outer darkness,” among others. Sometime between April 1830 and the late 20th century, somebody, somewhere referred to the fate of the sons of perdition as “outer darkness.” Like a vicious rumor, this erroneous doctrine caught on as a wildfire. Every missionary who has ever taught the Plan of Salvation has used the term “outer darkness” to refer to the fate of the sons of perdition. Because of this unfortunate, incorrect doctrinal tradition, the reader is usually confused by Alma’s description of “outer darkness” in this verse. Let me suggest that the term “outer darkness” refers to just what Alma is talking about—spirit prison.
If the scriptures are to be our guide, then let’s refer to them to answer this question. The term “outer darkness” appears in the following passages: Matt 8:12, Matt 22:13, Matt 25:30, Alma 40:13, DC 101:91, and DC 133:73. In none of these passages is the author referring to the sons of perdition. All of them are referring to the punishment of the wicked in spirit prison. On the other hand, let’s examine the scriptures about the sons of perdition. The most descriptive is found in DC 76:31-39. Neither this passage, nor any other which discusses the fate of the sons of perdition, ever uses the term “outer darkness.” Rather, the scriptures refer to this terrible place as perdition (Rev 17:8).
Bruce R. McConkie
“Hell is referred to as outer darkness. At death the spirits of the wicked ’shall be cast out into outer darkness; there shall be weeping, and wailing, and gnashing of teeth, and this because of their own iniquity, being led captive by the will of the devil. Now this is the state of the souls of the wicked, yea, in darkness, and a state of awful, fearful looking for the fiery indignation of the wrath of God upon them; thus they remain in this state, as well as the righteous in paradise, until the time of their resurrection.’ (Alma 40:13-14.) So complete is the darkness prevailing in the minds of these spirits, so wholly has gospel light been shut out of their consciences, that they know little or nothing of the plan of salvation, and have little hope within themselves of advancement and progression through the saving grace of Christ. Hell is literally a place of outer darkness, darkness that hates light, buries truth, and revels in iniquity.” (Mormon Doctrine, p. 551)