"Hell" is the English rendering of two different Greek words in the N.T.

The English word is from the Anglo-Saxon hel, Genitive case helle = a hidden place, from the Anglo-Saxon helan = to hide.

It is in the N.T. used as the translation of two Greek words :--

I.  Gehenna.  Gr. geenna.  This is the transliteration of the Heb. Gai' Hinnom, i.e. the Valley of Hinnom or "the Valley" of [the sons of] Hinnom, where were the fires through which children were passed in the worship of Moloch.

In the O.T. Tophet was the Heb. word used, because it was a place in this valley.

In our Lord's day the idolatry had ceased, but the fires were still continually burning there for the destruction of the refuse of Jerusalem.  Hence, geenna was used for the fires of destruction associated with the judgment of God.  Sometimes, "geenna of fire".  See 2Kings 23:10.  Isa. 30:33.  Jer. 7:31, 32;  19:11-14.

Geenna occurs 12 times, and is always rendered "hell", viz. Matt. 5:22, 29, 30; 10:28; 18:9; 23:15, 33.  Mark 9:45, 47.  Luke 12:5.  Jas. 3:6.

The meaning which the Greeks put upon it does not concern us; nor have we anything to do with the imaginations of the heathen, or the traditions of Jews or Romanists, or the teachings of demons or evil spirits, or of any who still cling to them.

The Holy Spirit has used it as one of the "words pertaining to the earth", and in so doing has "purified" it, "as silver tried in a furnace" (see notes on Ps. 12:6).  From this we learn that His own words "are pure", but words belonging to this earth have to be "purified".

The Old Testament is the fountain head of the Hebrew language.  It has no literature behind it.  But the case is entirely different with the Greek language.  The Hebrew Sheol is a word Divine in its origin and usage.  The Greek Hades is human in its origin and comes down to us laden with centuries of development, in which it has acquired new senses, meanings, and usages.

Seeing that the Holy Spirit has used it in Acts 2:27, 31 as His own equivalent of Sheol in Psalm 16:10, He has settled, once for all, the sense in which we are to understand it.  The meaning He has given to Sheol in Ps. 16:10 is the one meaning we are to give it wherever it occurs in the N.T., whether we transliterate it or translate it.  We have no liberty to do otherwise, and must discard everything outside the Word of God.

The word occurs eleven times (Matt. 11:23; 16:18.  Luke 10:15; 16:23.  Acts 2:27, 31.  1Cor. 15:55.  Rev. 1:18; 6:8; 20:13, 14); and is rendered "hell" in every passage except one, where it is rendered "grave" (1Cor. 15:55, marg. "hell").

In the R.V. the word is always transliterated "Hades", except in 1Cor. 15:55 (where "death" is substituted because of the reading, in all the texts, of thanate for hade), and in the American R.V. also.

As Hades is the Divine Scriptural equivalent of Sheol, further light may be gained from Ap. 35, and a reference to the 65 passages there given.  It may be well to note that while "Hades" is rendered "hell" in the N.T. (except once, where the rendering "the grave" could not be avoided), Sheol, its Hebrew equivalent, occurs 65 times, and is rendered "the grave" 31 times (or 54%);  "hell" 31 times (4 times with margin "the grave", reducing it to 41.5%); and "pit" only 3 times (or 4.5 %).

"The grave", therefore, is obviously the best rendering, meaning the state of death (Germ. sterbend, for which we have no English equivalent); not the act of dying, as an examination of all the occurrences of both words will show.

1.  The rendering "pit" so evidently means "the grave" that it may at once be substituted for it (Num. 16:30, 33.  Job 17:16).

2.  The rendering "the grave" (not "a grave", which is Hebrew keber or bor) exactly expresses the meaning of both Sheol and Hades.  For, as to direction, it is always down: as to place, it is in the earth: as to relation, it is always in contrast with the state of the living (Deut. 32:22-25 and 1Sam. 2:6-8); as to association, it is connected with mourning (Gen. 37:34, 35), sorrow (Gen. 42:38.  2Sam. 22:6.  Ps. 18:5;  116:3), fright and terror (Num. 16:27, 34) mourning (Isa. 38:3, 10, 17, 18), silence (Ps. 6:5; 31:17.  Ecc. 9:10), no knowledge (Ecc. 9:5, 6, 10), punishment (Num. 16:29, 34.  1Kings 2:6, 9.  Job 24:19.  Ps. 9:17 (R.V. = re-turned), corruption (Ps. 16:10.  Acts 2:27, 31); as to duration resurrection is the only exit from it (Ps. 16:11.  Acts 2:27, 31; 13:33-37.  1Cor. 15:55.  Rev. 1:18; 20:5, 13, 14).