Here are two verses that critics of the Book of Mormon often fail to cite, let alone interact with on any meaningful exegetical level, refuting their claim that the Book of Mormon teaches the "traditional" view of Hell and its duration:
Nevertheless, after wading through much tribulation, repenting nigh unto death, the Lord in mercy hath seen fit to snatch me out of an everlasting burning, and I am born of God. (Mosiah 27:28)
But I was racked with eternal torment, for my soul was harrowed up to the greatest degree and racked with all my sins. (Alma 36:12)
And yet, such torments did not last forever; they lasted three days (Alma 36:16).
On the issue of "eternal" as understood by ancients, see, for example:
