I have a tendency to try to treat Scripture as literal as possible within the context. But if the context makes clear that symbolism is being used or sometimes a different aspect of the context, then that takes priority.
For example, the “eternal fire” that burned Sodom and Gemorrah, which is used as an example of what will happen to the lost (in Jude 1:7). Since we are told clearly, twice, that “our God is a consuming fire”, the “eternal fire” that was used to destroy those two cities was “from the Eternal One” and could not be put out by any human means - it burned until its purpose was fulfilled. [By the way, have you heard about the new scientific finding that S & G were destroyed, at about the time of Abraham/Lot by an exploding meteorite over the area? Exciting archeological find!]
So the context makes clear it was not a fire that kept on burning S & G forever. And the specific statements by Jesus about Gehenna destroying both body and soul make clear that the lost will have neither a body or soul burning forever. Of course, Isaiah backs that up with his description of the dead bodies in the “Final Fire”, that burns forever, in 66:24.
Regarding what C.S. Lewis said (a hell where God has given a person over to their own desires), that could fit with being “cast into outer darkness”, which could be perhaps another universe in another dimension where there is no Redeemer, but that still has the One Who is perfect love keeping His creatures alive so they can suffer non-stop for time beyond time. Inconsistent.
So being “cast into outer darkness” would be one way to describe becoming non-existant, since God/Christ/Spirit is Light, and is everywhere present.
Psalm 37 has some interesting statements:
“Fret not yourself because of evildoers; be not envious of wrongdoers! For they will soon fade like the grass and wither like the green herb.”
“For the evildoers shall be cut off, but those who wait for the Lord shall inherit the land.”
“In just a little while, the wicked will be no more; though you look carefully at his place, he will not be there. But the meek shall inherit the land and delight themselves in abundant peace.”
“For the arms of the wicked shall be broken, but the Lord upholds the righteous.”
“But the wicked will perish; the enemies of the Lord are like the glory of the pastures; they vanish—like smoke they vanish away.”
“Wait for the Lord and keep his way, and he will exalt you to inherit the land; you will look on when the wicked are cut off.”
“For there is a future for the man of peace. But transgressors shall be altogether destroyed; the future of the wicked shall be cut off.”
Seems pretty clear, doesn’t it…