What did Jesus mean by Gehenna?
Gehenna is the Valley of Hinnom outside Jerusalem, a place linked in the Old Testament with child sacrifice and judgment. Jesus used the name for the place of final judgment.
In the Old Testament the Valley of Hinnom was where some kings of Judah sacrificed children, and Jeremiah said it would become a valley of slaughter. By Jesus' time its name stood for God's final judgment, and most English Bibles translate it as hell.
31They have built the high places of Topheth, which is in the valley of the son of Hinnom, to burn their sons and their daughters in the fire, which I didn’t command, nor did it come into my mind. 32Therefore behold, the days come”, says Yahweh, “that it will no more be called ‘Topheth’ or ‘The valley of the son of Hinnom’, but ‘The valley of Slaughter’; for they will bury in Topheth until there is no place to bury.
Jeremiah 7:31-32 (WEB) · context
22But I tell you that everyone who is angry with his brother without a cause will be in danger of the judgment. Whoever says to his brother, ‘Raca!’ will be in danger of the council. Whoever says, ‘You fool!’ will be in danger of the fire of Gehenna.
Matthew 5:22 (WEB) · context
47If your eye causes you to stumble, throw it out. It is better for you to enter into God’s Kingdom with one eye, rather than having two eyes to be cast into the Gehenna of fire,
Mark 9:47 (WEB) · context
The good news
Jesus came to save you from this
God loves you and gave His Son so that whoever believes in Him should not perish.