Of course I know that. I'm a NT Greek teacher.
That's not the issue. Because Gehenna was a burning rubbish dump outside of Jerusalem, it was used as a picture of the final destiny of the damned, death and Hades. It is not a place of non-existence. It's a place of conscious torment according to the biblical revelation.
When the prodigal son was in the far country, he was “lost” (apololos), i.e., estranged from the blessings of his home, but he was not annihilated. Jesus affirmed that he came to save that which stands lost (apololos). The perfect tense describes a present condition which has resulted from previous activity. The Lord did not come to save folks who were in a state of non-existence!
“In every instance where the word apollumi is found in the New Testament, something other than annihilation is being described” (Morey, 90).
See also William V Crockett’s article, ‘
Wrath that endures forever’ (1991).
Oz