There are four main words used for Hell in the Bible. The first one is Sheol. Sheol is a Hebrew word meaning “the grave”. This is where it is believed both righteous and wicked people go after death. Another word used that has a similar meaning to Sheol is Hades. Then, in the New Testament, it talks about Gehenna. This place is described as the final punishment for the wicked. It also has ties to the Valley of Hinnom, which I’ll talk more about in the next paragraph. The final name used for Hell is Tartarus. This is also used in the New Testament and is used to refer to a place of punishment for fallen angels. It’s important to distinguish the difference between these terms and know which one the passage you’re looking at refers to.
Now, I previously mentioned the Valley of Hinnom. In the Old Testament this valley was used as a site of child sacrifice to the Canaanite god Molech. People sacrificed their children by fire to this false god, until king Josiah put an end to it. This valley’s name was changed to “valley of slaughter” by the prophet Jerimiah. In the New Testament we see this place take a metaphorical meaning in the afterlife. In Mathew 10:28 Jesus uses the name Gehenna (or the Valley of Hinnom) when He says “Do not be afraid of those who kill the body but cannot kill the soul. Instead, fear the One who can destroy both soul and body in hell (Gehenna).” The fact that the physical location of Gehenna took on this metaphorical meaning highlights the extreme consequences of sin.