It is clear that Jesus did not view a human personality as just the body.Hell does not have a fire that burns forever. It is a mistake to lump "Hades" together with "Gehenna" and call them both "Hell." Hades is the common grave of mankind. Gehenna is a fiery dump of ancient days, mentioned by Jesus to illustrate what happens to a dead body when thrown there---complete destruction.
.He warned that evil people will be consigned to eternal annihilation and symbolized that with the fiery dump
He warned that evil personalities would experience hellish environments. Whether those environment were permanent or not, may or may not be clear. The fact that such could be experienced is what Jesus was warning about
If the use of fire symbolizes compete destruction, then what feeds the fire that make it eternal?Also, any mention of "fire" is a way of symbolically speaking of utter destruction. So when you see fire mentioned, it symbolizes complete annihilation so that the person no longer exists.
Also to note - sometimes God is associated with light, and one of the spectrums of light is created through fire.
So using fire or light to "symbolize" God and other such notions, isn't overly helpful.