I’ve always understood that many of the references in the bible to heaven and hell refer to paradise and spirit prison–thus, the images of sulfur and burning. Therefore that’s why there’s no discussion of the three degrees in the Old Testament or most of the New Testament.
The references we read in the Bible which refer to Heaven and Hell are able to have multiple meanings, depending on the verse and what the verse specifies.
Hell, within scripture, surely represents two places: spirit prison and outer darkness. However, depending on your personal interpretation Hell within scripture can mean any state, or glory, by which the individual is not in the presence of God the Father, as such, the individual has come to the understanding that they will not have “eternal lives.”
Some scriptures are pretty clear when speaking of Hell as it pertains to a place of waiting, a waiting place by which they will be tormented by their choices, sins, in life before their resurrection. These scriptures obviously are speaking with regard to spirit prison. This is clearly emphasized within the Book of Mormon in the following verses.
1. Alma 40:12-14 (particularly verse 13)
12 And then shall it come to pass, that the spirits of those who are righteous are received into a state of happiness, which is called paradise, a state of rest, a state of peace, where they shall rest from all their troubles and from all care, and sorrow.
13 And then shall it come to pass, that the spirits of the wicked, yea, who are evil—for behold, they have no part nor portion of the Spirit of the Lord; for behold, they chose evil works rather than good; therefore the spirit of the devil did enter into them, and take possession of their house—and these 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.
14 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.
2. 2 Nephi 9:12-14 (verse 12, and 14)
12 And this death of which I have spoken, which is the spiritual death, shall deliver up its dead; which spiritual death is hell; wherefore, death and hell must deliver up their dead, and hell must deliver up its captive spirits, and the grave must deliver up its captive bodies, and the bodies and the spirits of men will be restored one to the other; and it is by the power of the resurrection of the Holy One of Israel.
13 O how great the plan of our God! For on the other hand, the paradise of God must deliver up the spirits of the righteous, and the grave deliver up the body of the righteous; and the spirit and the body is restored to itself again, and all men become incorruptible, and immortal, and they are living souls, having a perfect knowledge like unto us in the flesh, save it be that our knowledge shall be perfect.
14 Wherefore, we shall have a perfect knowledge of all our guilt, and our uncleanness, and our nakedness; and the righteous shall have a perfect knowledge of their enjoyment, and their righteousness, being clothed with purity, yea, even with the robe of righteousness.
Heaven also is able to have multiple meanings even with the Bible. If I draw your mind to Paul’s words who spoke of a “3rd Heaven” as a Latter-Day Saint we may begin to think about which kingdom of glory is the 3rd Heaven? I would assume the Telestial Kingdom. However, when we typically read verses pertaining to a place of peace and happiness before the resurrection, then we know it is referring to paradise within the spirit world.
As pertaining to the reason why heaven and hell aren’t mentioned in the Old Testament or the majority of the New Testament is pure speculation. The reason this is not mentioned could be due to a number of variables, mistranslation being one of them. It could also have been a result of books burned, or books as of yet undiscovered, or hidden by God (imagine if Alma’s words were removed from the Book of Mormon, or not added).
Thus we see the power and wisdom of God in bringing forth the Book of Mormon.