He says it is a place of eternal torment (Luke 16:23), of unquenchable fire (Mark 9:43), where the worm does not die (Mark 9:48), where people will gnash their teeth in anguish and regret (Matt. 13:42), and from which there is no return, even to warn loved ones (Luke 16:19–31). He calls hell a place of “outer darkness” (Matt. 25:30), comparing it to “Gehenna” (Matt. 10:28), which was a trash dump outside the walls of Jerusalem where rubbish was burned and maggots abounded. Jesus talks about hell more than he talks about heaven, and describes it more vividly. There’s no denying that Jesus knew, believed, and warned about the absolute reality of hell.
As C.S. Lewis writes, “In the long run the answer to all those who object to the doctrine of hell is itself a question: ‘What are you asking God to do?’ To wipe out their past sins and, at all costs, to give them a fresh start, smoothing every difficulty and offering every miraculous help? But he has done so, on Calvary. To forgive them? They will not be forgiven. To leave them alone? Alas, I am afraid that is what he does.”