If there is a fiery hell where all unbelievers go...?

What about the scripture at Ecclesiastes 9:5-6? For the living are conscious that they will die; but as for the dead, they are conscious of nothing at all, neither do they anymore have wages, because the remembrance of them has been forgotten. 6�Also, their love and their hate and their jealousy have already perished, and they have no portion anymore to time indefinite in anything that has to be done under the sun. And if you believe in an immortal soul, how could it be burned, or be thirsty, or hungry? Just when would you be put into this furnace? As soon as you die? What is the judgement on the last day? Rev 20 says that the devil, hades, death will all be put into the lake of fire, how could you put death and hades into the lake of fire? Especially the devil who is supposed to live in the lake of fire or hades which is supposed to be the lake of fire? Does this not suggest that the devil, death, hades will cease to exist, just as Rev 21:4 states?