Tartarus is the place where the most wicked fallen angels/demons are kept.
Gehenna is a garbage dump in the Valley of Hinnom south west of Jerusalem. It was always burning and represents the place that is similar to what we consider to be hell.
Israel burned their children alive there as sacrifices to the idols Chemosh, Moloch and Baal. After returning from Babylon, the Jews used it as an open pit for a garbage dump for executed criminals, decaying food and human excrement. When it became full it was set on fire.
The Jews returned from Babylon before Jesus. So Gehenna was there before and during Jesus.
Hades is found eleven times only in the New Testament, and is rendered by the word Hell ten times, and once by the
word Grave. 1 Cor. 15:55. It is universally allowed by critics that Hades corresponds in meaning with Sheol; and this
is confirmed by the fact that the Septuagint, [note 1] which is the Greek translation of the Hebrew Scriptrues, made in
part about three hundred years before Christ, has rendered Sheol by the word Hades sixty times out of sixty-four
instances where it occurs. However, with regard to the meaning of the word, in the New Testament, it may be well to
have independent testimony.
[note 1: The Septuagint, or Seventy, sometimes written the LXX., is so called from the fact or tradition of its being the joint labor of
seventy learned Jews in the time of Ptolemy Philadelphus. It was in use in our Savior's time]
Meaning and usage of Hades. A theologian, equally learned as a scholar, judicious as a critic, and impartial as a
commentator, says of Hades, --
"In my judgment, it ought never in Scripture to be rendered Hell, at least in the sense wherein that word is universally
understood by Christians. It is very plain that neither in the Septuagint version of the Old Testament, nor in the New,
does the word Hades convey the meaning which the present English word Hell, in the Christian usage, always conveys
to our minds. The attempt to illustrate this would be unnecessary, as it is hardly now pretended by any critic that this is
the acceptation of the term in the Old Testament."[note 2]
[note 2: DR. CAMPBELL, "Preliminary Dissertations," Diss. Vi. Part ii. LE CLERC affirms that "neither Hades nor Sheol ever
signify in the Sacred Scripture the abode of evil spirits, but only the sepulchre, or the state of the dead." And this is also the
testimony of GROTIUS and other learned men. -- De Elingenda, inter Dissentientes Christianos, Sententia Liber. par. vii. See also
POOLE's "Continuators on Like," xvi. 19-30. These testimonies, which might be added to indefinitely, are enough to show that
Hades in the New Testament is simply the Greek form of what Sheol is in the Old; and therefore that "Hell" does not convey to the
people of this day the same idea which Hades conveyed to the people in the time of Christ. It is plain, too, that at the time our
translation was made, "Hell" in English did not bear the exclusive meaning it has now. The Apostle's Creed, so called, is proof of
this, when it says, that Christ after his crucifixion "descended into hell!" Surely the Protestant English Church did not mean to say
that Christ went into a place of endless woe. Therefore, as Prof. STUART says, "Hell, in this document, means the underworld, the
world of the dead, and so it has ben construed by the most intelligent critics of the English Church." It has been very correctly said
that "Hell, in its primitive signification, corresponded perfectly in meaning with Hades. It comes from the Anglo-Saxon, helan, to
cover or hide; hence the tiling or slating of a house is called, in Cornwall, helling to this day; and the covers of books in Lancashire
by the same name -- so the literal import of the original word Hades was formerly well expressed by it." CAMPBELL,
DODDRIDGE, CLARKE, PARKHURST, and others. I saw lately in an English newspaper, an account of an accident which
happened to a Slater, who "fell from the roof while engaged in helling it."]
And now let us turn to the New Testament, and we shall find that Hades, in its literal usage, is the equivalent of Sheol,
I. The grave, the underworld, or place of the dead.