"Gehenna" therefore soon became a figurative equivalent for "hell." Hell, like paradise, was created by God (Sotah 22a);
Gehinnom (Heb. גֵּי בֶן־הִנֹּם, גֵּי בְנֵי הִנֹּם, גֵּיא בֶן־הִנֹּם, גֵּיא הִנֹּם; Gr. Γέεννα; "Valley of Ben-Hinnom, Valley of [the Son (s) of] Hinnom," Gehenna), a valley south of Jerusalem on one of the borders between the territories of Judah and Benjamin, between the Valley of *Rephaim and *En-Rogel (Josh. 15:8; 18:16). It is identified with Wadi er-Rababi.
…..During the time of the Monarchy, Gehinnom, at a place called Topheth, was the site of a cult which involved the burning of children (II Kings 23:10; Jer. 7:31; 32:35 et al.; ). Jeremiah repeatedly condemned this cult and predicted that on its account Topheth and the Valley of the Son of Hinnom would be called the Valley of the "Slaughter" (Jer. 19:5–6).
In Judaism the name Gehinnom is generally used as an appellation of the place of torment reserved for the wicked after death. The New Testament used the Greek form Gehenna in the same sense.
Jesus undoubtedly knew what the Jews, believed about hell. If the Jews were wrong, why didn’t Jesus tell them there was no hell, no eternal punishment etc? Why would Jesus teach “eternal punishment,” etc. to Jews who believed, "The Lord, the Almighty, will punish them on the Day of Judgment by putting fire and worms into their flesh, so that they cry out with pain unto all eternity," which would only encourage and reinforce their beliefs?
Are you aware that there are two distinct Gehenna traditions that developed within Judaism?
1. The Apocalyptic-Infernalist Tradition (Enoch Tradition)
Gehenna began to replace Sheol as the place of the dead. It soon turned from a place of
physical destruction on Earth to a
place of postmortem underworld torment. Jews, and then Christians, began to equate Gehenna (Jerusalem's legendary garbage dump) with a place of fiery judgment after death.
2. The Historic-Prophetic Tradition (Jeremiah Tradition)
Jeremiah tells us plainly what his view of Gehenna is ("Valley of the Slaughtered"), referring to the historical, literal events that took place there. In this definition of Gehenna, Jeremiah is recalling the literal fire that came to consume Jerusalem for its sins and to cleanse the land of sin's defilement.
Please reread Jesus' use of Gehenna and you will clearly see that he is following Jeremiah's straightforward use of Gehenna. Take a look at Jesus' ministry and you will clearly see parallels between Him and Jeremiah. Jesus employs the use of Gehenna NOT to prophesy afterlife destruction, but rather he is prophesying the impending fall of Jerusalem to Rome in AD 70.
In Jesus' mission to redefine our vision of God, he regularly challenged and outright broke the traditions of the elders. He never "encouraged and reinforced" the beliefs of the Jews concerning MANY things, so why do you assume he would "encourage and reinforce" their belief that Gehenna equates Hell? His listeners could never assume that Jesus always meant what the other rabbis meant when he used other common terms like "temple", "kingdom", etc. Thus, we should not accept too readily that Jesus was using Gehenna in the way that the other rabbis did.
If you accept that Jesus is commissioning Jeremiah's use of Gehenna then you will also see the hope in the fate of Gehenna. Jeremiah's final reference to Gehenna in the New Covenant Kingdom prophecies take a REDEMPTIVE twist. (Jeremiah 31: 38-40 "The whole valley where dead bodies and ashes are thrown will be Holy to the LORD.") The New Covenant promises that not only will Jerusalem be rebuilt, but the valley of ashes and bodies will reclaimed and sanctified.
It is so unfortunate that the Christian tradition has decided to follow the Enoch tradition instead of the biblical tradition of Jeremiah and JESUS. If Jesus did not mean hell when he spoke about Gehenna, then why do we continue to associate Gehenna with hell?
"We ought to also notice the irony of the Church utilizing the very place where God became violently offended by the literal burning of children as our primary metaphor for the final and eternal burning place of God's children. Thus, God becomes the very Molech who decrees that angels must deliver his children to the flames, even though this was the very reason that He ordered Hinnom be desecrated in the first place!"
Her Gates Will Never Be Shut, Bradley Jersak