For many people today, the concept of hell is outdated, a relic of the past that has served its purpose and can be safely done away with. But for those who are interested in what Jesus taught, hell cannot be so easily dismissed. In fact, no other biblical figure speaks about hell more often than Jesus Christ.
As the one who was God in human flesh, no one knows more about hell than Jesus Christ. So, first, let's look at the different terms and images Jesus uses to describe hell, and then explore what he actually says about it.
The two most common words for hell are hades and gehēnna. Hades was the Greek word for the realm of the dead, but Jesus uses it more specifically to refer to a place of torment (Luke 16:23), a place that is the opposite of heaven (Matt 11:23). Originally gehēnna referred to Hinnom Valley south of Jerusalem, where centuries earlier child sacrifice was practiced (2 Kgs 23:10; Jer 7:32). By the time of Jesus, gehēnna was a picture of hell, such that Jesus warns "fear him who can destroy both soul and body in hell [gehēnna]" (Matt 10:28).
Jesus often combines this word with fire, a very common image of hell. As such it communicate the horror of the place, as in Matthew 5:22 when he warns "whoever says, 'You fool!' will be liable to the hell [gehēnna] of fire." Another common picture of hell is darkness. Jesus warns that those who refuse to enter the kingdom of God by repentance and faith "will be thrown into the outer darkness. In that place there will be weeping and gnashing of teeth" (Matt 8:12).
What, then, did Jesus actually teach about hell? We can summarize it like this: hell is the place of conscious, eternal torment where people experience God's punishment for their sin. Yes, hell is "the eternal fire prepared for the devil and his angels" (Matt 25:41), but those who join them in their rebellion against God (Matt 11:20–24). The horror of hell is such that Jesus says, "if your hand causes you to sin, cut it off. It is better for you to enter life crippled than with two hands to go to hell, to the unquenchable fire" (Mark 9:43). For those who do not enter the narrow door of faith and repentance in Jesus (Luke 13:24) a place of weeping and gnashing teeth awaits them (Luke 13:28).
At the end of human history, everyone will appear before Jesus Christ, where he will divide humanity into "sheep" (those who demonstrate their faith in Jesus through their good works) and the "goats" (those who did not trust in Jesus Christ). The sheep will receive eternal life, while the goats "will go away into eternal punishment" (Matt 25:46).
Jesus uses strong language about hell because it is real and unspeakably horrible. But he not only warned of the dangers of hell; he offered the way out. He lived a life of perfect obedience, died a sacrificial death on the cross for our sins, and rose from the dead to defeat sin, death, and the devil. He invites everyone to trust in him to receive eternal life rather than the eternal punishment that everyone deserves for their sin.