Here is the worst part of the Lake of Fire: "And the smoke of their torment will rise for ever and ever. THERE WILL BE NO REST day or night for those who worship the beast and its image, or for anyone who receives the mark of its name." (Revelation 14:11)

Have you ever suffered from insomnia? You cannot think about anything, you cannot focus on anything, you cannot do anything. You just have one overwhelming thought in your mind: to go to sleep. Imagine that forever and ever. That is far worse than any physical pain one can experience.

Meanwhile, there will be many sensual delights in the New Jerusalem, but the best one will be the freedom to sleep any time you want.