Jud 1:22-23 And have mercy on those who doubt; (23) save others by snatching them out of the fire; to others show mercy with fear, hating even the garment stained by the flesh.
Clearly the fire cannot be completely literal; a literal fire consumes fuel, using oxygen to produce heat and smoke. Fire in this Jude passage describes destruction.
There are some other Bible passages like it that are also understood to mean that wicked people will suffer excruciating torture eternally.
Mar 9:47-48 And if your eye causes you to sin, tear it out. It is better for you to enter the kingdom of God with one eye than with two eyes to be thrown into hell, (48) ‘where their worm does not die and the fire is not quenched.’
Jesus was quoting from:
Isa 66:24 “And they shall go out and look on the dead bodies of the men who have rebelled against me. For their worm shall not die, their fire shall not be quenched, and they shall be an abhorrence to all flesh.”
In this passage the Old Testament prophet of God described the time that is still future when God’s righteous kingdom will be established on the earth. God’s judgment will be executed on those who rebel against him. It is not “souls” that are described as being tortured, but “dead bodies” as being burnt. In Old Testament times worshippers of foreign gods such as Baal and Moloch sacrificed their children in the Valley Of Hinnom just outside Jerusalem. The “hell” in Mar 9:47 is translated from the Greek word for the Valley of Hinnom. Some ancient writers claim a fire was continuously burning there in the first century, and was used to destroy rubbish and the bodies of executed criminals. Whether or not this is the case, the name of the Valley of Hinnom came to be despised.
This fire is not literal. Nor are the worms literal; even those people who believe in the doctrine of the immortal soul do not believe in the doctrine of the immortal worm.
What does this Mark passage teach then? Consider another colourful symbolic passage.
Rev 20:13-15 And the sea gave up the dead who were in it, Death and Hades gave up the dead who were in them, and they were judged, each one of them, according to what they had done. (14) Then Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire. (15) And if anyone’s name was not found written in the book of life, he was thrown into the lake of fire.
The interpretation given in Rev 20:14 is that the fire describes “the second death”. The wicked will be destroyed after facing judgment. That is the consistent teaching of scripture.
2Th 1:9 They will suffer the punishment of eternal destruction, away from the presence of the Lord and from the glory of his might,
Eternal torture cannot reasonably be described as “eternal destruction”. It is horrible to contemplate the idea that some people have; that God will keep alive everyone to whom he does not give eternal life — for eternal torture. Not only would this be extremely cruel, it is not what the Bible teaches.