🔼The concept of Sheol
The name Sheol (mostly spelled שאול but sometimes שאל) belongs to the difficult concept of what happens in death, as depicted in the Hebrew Old Testament. For all sorts of reasons, this Hebrew view is somewhat different from the one used in the New Testament (where the realm of death is referred to as αδης, hades or Hades, which is a word that already existed in Greek mythology — Acts 2:27), but only because the authors of the New Testament could obviously afford a different angle on the whole thing. But both substantially differ from the heaven-and-hell model that we moderns are so accustomed too, and which appears to be mostly based on pagan models rather than on a Biblical one (to give a hint: the signature phrase "heaven and hell" does not occur once in the entire Bible).
The Hebrew authors were far less concerned with the individual than we moderns are. In fact, where we like to see the Bible as a string of hero stories, to the authors it was mostly the story of the evolution of Israel as continuously brought about by YHWH (aided by human agents). And where we like to think that one's final destination is wholly determined by one's own life, the authors recognized the importance of one's offspring. The authors knew that the Kingdom of God will be peopled by folks who will live eternally. That means that their ancestors had in fact their offspring's eternal life in them. And that means that their ancestors had lived among other folks, while they had eternal life in them and the other folks didn't, and no difference between the two was obvious. But that's not all.
Remember how life began: God had created the dust of the earth. He gathered that dust into a vital composition, and breathed His breath into it. That made the thing a living being, set apart from other things (Genesis 2:7). When God entered into a covenant with Abraham, He promised that his seed would be like the dust of the earth (Genesis 13:16). The apostle Paul explained that those with faith were Abraham's seed (Romans 4:11, Galatians 3:7) and thus like the dust of the earth. What God did in the beginning He did again, namely gather that dust into a vital composition and release into it His Holy Spirit (Acts 2:4). That means that the Body of Christ is not just another club, but relates to other human organizations the way a living being relates to a stone. But it also means that the "body of Abraham" (which is the proto-body of Christ) had life in it, even though it existed in a time during which that kind of life did not yet exist. But that's not all either.
In Hebrew, one's soul was not some ghostly ethereal essence, but rather one's condition of being alive (read our extensive article on the word נפש, nepesh, meaning soul). The Hebrew authors weren't so much concerned about the post-life destination of the individual, but rather about the real-life destination of humanity, here on earth. In this context, the Hebrews were much more concerned about one's part in the salvation or preservation of humanity, namely one's "name," that is to say, one's personhood relative to the rest of humanity. That means that one's personal name/personhood might be passed onto one's offspring, and this happens in the Bible most clearly with Jacob, whose name and nickname Israel became synonymous with his offspring. And that means that the God of Abraham, Isaac and Jacob is a God of the living and not of the dead (Mark 12:26-27). Ergo: a person may be in the grave but not dead at all, and a person might be dead as a doornail while making silly millions in some office (Ephesians 2:1).
All this taken into account, the name Sheol marks a falling apart, either of one's private body, one's name or one's offspring. Sheol is the "place of dissipation" (Job 7:9) or "turning-to-dust" (Job 17:16), which on the individual level comes down to the grave, and on a social level to family feuds and dispersal. Given all the human individuals at large, it's really quite special to have a nation named after you and a falling apart of that nation means a ceasing to exist of a name of someone whose private body has decayed long prior. The body of the Holy One is that human collective that has been together in some form or other since the beginning of humanity, and which will never fall apart (Psalm 16:10).
Here and there the name Sheol appears in tandem with the name Abaddon, which means destruction (Psalm 88:11). It's also known as the pit (בור, bor; Isaiah 38:18), the abyss (αβυσσος, abussos; Luke 8:31, Romans 10:7) and possibly also Gehenna (Matthew 5:22, James 3:6), although Gehenna appears to correspond to a different place, namely one of fire and active punishment also known as the lake of fire (Revelation 19:20).
Sheol appears to denote not only the realm of death but also the quality of mortality while still living; as the Psalmist notes: "the cords of Sheol entangled me" (Psalm 18:5) and "the pangs of Sheol laid hold on me" (Psalm 116:3). It seems from this context that the Body of the Holy One would not see decay and that Jesus declared that the gates of Hades would not overpower the church built on the rock of faith (and not on Peter; Matthew 16:18).
🔼The name Sheol in the Bible
As a rule, Sheol is the destiny of all living (Job 30:23), although there are some exceptions (Enoch, Elijah, and of course Jesus of Nazareth and the whole Body of Christ). People usually go there after death, but on occasion someone descends into Sheol alive. It's not clear what to think of that, but perhaps a live descent into Sheol may denote besides a literal sinking into the earth (which happened to Korah and company; Numbers 16:33) perhaps also a descent into madness; the state of mind that is unfocused and dispersed (Psalm 30:4, 55:15). Folks who are in Sheol are weak (Isaiah 14:10, Psalm 88:4) and experience very little (Ecclesiastes 9:5) but may be retrieved from there to regain their senses (1 Samuel 28:13) and even their lives (1 Samuel 2:6), although in normal circumstances it's the place of no return (Job 10:21, Isaiah 26:14) until the resurrection (Isaiah 26:19, Ezekiel 37:12).
Sheol is obviously not a physical place, but it is metaphorically spoken of as a land (Job 10:21) and having gates, which would make it a city (Isaiah 38:10, Psalm 9:14), but also as having a mouth (Numbers 16:30) and throat (Isaiah 5:14). It's a place of "darkness and deep shadow, utter gloom and deep shadow without order" (Job 10:21-22), and of silence (Psalm 94:17). There is no activity, planning or wisdom in Sheol (Ecclesiastes 9:11). The folks in there are mere shadows (Proverbs 21:16) and do little else than sleep (Jeremiah 51:39). Contrary to underworlds in other religions, the Hebrew realm of death wasn't run by anyone in particular. Still the Lord rules even there (Amos 9:2, Psalm 139:8).
The transition towards Sheol is generally described as a going down (Genesis 37:35), which should be viewed juxtaposed with a movement towards heaven as a "going up" (Isaiah 7:11, Ezekiel 31:14, Job 11:8). This downward motion may, to some extent, describe one's body being deposited in a subterranean grave, but it probably has much more to do with a motion away from unity and towards dispersal. The same upward and downward motion is expressed in a motion towards Jerusalem (up, that is unity and heaven) or away from Jerusalem (down, which is diaspora and earth). The "deepest depth of Sheol" describes complete dispersal, or maximum entropy (Deuteronomy 32:22, Psalm 86:13).
🔼Etymology of the name Sheol
Scholars have looked far and wide to explain the name Sheol via words found in other languages but no explanation wholly satisfied and we're back to the obvious, albeit difficult to explain, namely that the name Sheol comes from the verb שאל (sha'al), meaning to ask, inquire, borrow, beg:
The name Sheol means the same thing as the name Saul, namely Asked For, which is obviously curious enough to have scholars franticly look for another explanation, to no avail.
Some say that Sheol was named such because it's never satisfied and will always ask for more (Proverbs 27:20 and 30:16). But perhaps the concept of Sheol originated as a place of rest after a life of trial (1 Kings 2:6).
Perhaps it even reflects the original sin: death is something we asked for when we ate from the fruit of the tree of knowledge of good and evil, just like our liberties were infringed when we asked for a king to rule over us (1 Samuel 8:7).