Behold the Severity of God

[Hell] is a profound and dreadful reality. To speak of it lightly, or not to speak of it at all, or to speak of it in a way that changes suffering into feeling nothing, simply proves that we do not grasp its horror. I know of no one who has overstated the terrors of hell. We can scarcely surpass the horrid images Jesus used. "Weeping and gnashing of teeth,"⁴ "their worm shall not die" (Mark 9:48); "unquenchable fire" (Matthew 3:12; Mark 9:43); "eternal fire" (Matthew 25:41); "the hell of fire" (Matthew 18:9); "eternal punishment" (Matthew 25:46); "anguish in the flame" (Luke 16:24). The point of all these is that we are meant to shudder. We are meant to tremble and feel dread. We are meant to recoil from the reality. Not by denying it but by fleeing from it into the arms of Jesus, who died to save us from it.

Revelation 14:11 is probably the most graphic New Testament statement of the eternal suffering of the unrepentant. "The smoke of their torment goes up for ever and ever; and they have no rest day or night." Torment forever and ever. The endless suffering of unrepentant sinners is a reality taught in Scripture and therefore good for us to know about.

John Piper, The Echo and the Insufficiency of Hell