A question that often arises in theological circles is, Did Jesus warn about Hell? The answer is a bit complicated. Jesus did speak about an abhorrent place of punishment, but He used the term Gehenna. The association of the word “hell” with Jesus is somewhat anachronistic. "Hell" is neither a Hebrew or a Greek word (both Old and New Testaments were written in those languages), nor did it primarily indicate "a place of torment." Biblical translators actually derived it from a secular German word - spelled hel - meaning nothing more than concealed or covered. The concept of a demon regulated horror-house was indeed derived from that word, but it actually evolved from Teutonic mythology. Hele was a goddess of the underworld in ancient folklore.
According to mythologists, Hel is the name of the Norse underworld, and its ruler. Hel/Hela, in Norse mythology, was the hideous daughter of the Giant Loki, banished to the netherworld, Helheim (literally, 'house of Hel'), world of the dead, by the Chief God, Odin. The distinctive looking Goddess, whose skin is black on one side, rules over the dead until Ragnarok and the coming birth of the new world. The name for the Christian world of torment "Hell" is derived from Hela's abode.
Originally, the Hebrew name was Gei Ben-Hinnom, “the valley of the sons of Hinnom, located South of Jerusalem: This developed into the Aramaic Gahanna. The Greek term was Geenna. It was a combination of the Aramaic and Greek spelling which produced the English, Gehenna. Jesus was referring to the infamous history of this valley in His warning of punishment.
The Valley of Hinnom rose to fame during the early Monarchy of Israel. In ancient Israel parents “passed children through the fire” (sacrificed their children) to the Canaanite god, Molech (2 Chronicles 28:3; 33:6; Jeremiah 7:31; 19:2–6). The place is called “Tophet / Topheth” in Isaiah 30:33. Molech was an idol, with a fire burning on the inside of the hollowed statue, with its hands outstretched. The hands would be scalding hot and the children would be placed on these hands. Sometimes, the parent strangled the children to save them from such a horribly painful death. Scholars suggest that the pagan priests beat the drums to cover up the screams of the baby as it was being incinerated.
Once this practice was abandoned, by the later Kings. The valley seemed to have become a location of potters. Pottery workshops, according to the “Associates for Biblical Research, pottery workshops were often located outside of town so as not to antagonize the residents of the city with the “strong and sickening” smoke from the kilns (Isaiah 30:33). The most famous pottery workshops seem to have been located in the Hinnom Valley. The references to a “Tower of Furnaces” in Nehemiah 3:1 and 12:38 seem to refer to an edifice overlooking the kilns in the Valley of Hinnom.
In later Judaism, Gehenna became a place where corpses of criminals, dead animals, and all manners of refuse were thrown to be destroyed. The Gehenna Valley had become a place of burning sewage, burning flesh, and garbage. Maggots and worms crawled through the waste. It was a place that was thought to have been utterly filthy, disgusting, and repulsive to the nose and eyes. Gehenna presented such a vivid image that Christ used it as a symbolic depiction of a place of eternal torment and constant uncleanness, where the fires never ceased burning and the worms never stopped crawling (Matthew 10:28; Mark 9:47–48).
The scholar Caleb Cook explains Jesus’ use of the imagery. Gehenna is clearly a place that we don’t want to go. It is a place outside the Kingdom of God, the idea of Gehenna being specifically a place where people are sacrificed to false Gods is important in getting a full picture of what Jesus is communicating. When Jesus contrasts being sent to Gehenna with being accepted into his Kingdom he is, at least in part, saying that when you refuse to live by Kingdom Values you are being sacrificed to a false God. Jesus is saying that you will be thrown into a place of destruction.
Furthermore, Jesus wants to build upon the Hebrew Bible’s concept of Sheol, meaning “grave” or “pit”. This was a place of total inactivity, not beyond God’s reach, but separated from Him. Sheol is devoid of love, hate, envy, work, thought, knowledge, and wisdom ( Ecclesiastes 9:6 Ecclesiastes 9:10 ). Descriptions are bleak: There is no light (Job 10:21-22 ; 17:13 ; Psalms 88:6 Psalms 88:12 ;143:3 ), no remembrance ( Psalm 6:5 ; 88:12 ; Eccl 9:5), no praise of God (Psalm 6:5 ; 30:9 ; 88:10-12 ; 115:17; Isa 38:18 ) no sound at all (Psalm 94:17 ; 115:17). Its inhabitants are weak, trembling shades (Job 26:5 ; Psalm 88:10-12 ; Isa 14:9-10 ) who can never hope to escape from its gates (Job 10:21 ; 17:13-16 ; Isa 38:10 ). Unlike Sheol, Jesus teaches us that this is a place of everlasting torment. Later, literature, Philosophy, and Theology have developed the concept of Hell far beyond this imagery.