There certainly isn’t any point to death being thrown with hades (and Satan, btw, so death doesn’t mean Satan there) into the lake of fire if the lake of fire involves annihilation in the sense held by annihilationists: if death is annihilated, that’s another way of saying God has decided not to kill anyone again (and/or send them to the spiritual state of hades).
I prefer not to regard the people outside the NJ as “immortal”, though, unless you mean “conditionally immortal”. They don’t have eonian life yet.
Which definitely refers to hopeful punishment (and expected salvation in the same day of the Lord to come), not annihilation, when Paul uses it to talk about handing the Stepmom-Sleeping Guy over to Satan for the whole-destruction of the flesh in 1 Cor 5:5.
Paul compares it to a birth-pang, which is dangerous but hardly hopeless annihilation (and is generally regarded as very hopeful) at 1 Thess 5:3 (talking about the same day to come).
Paul uses the term to describe people killed by God in the past at 1 Cor 10:10, which can hardly be annihilation unless the resurrection of the evil as well as the good is denied.
2 Thess 1:9 uses phrases similar to those found in Isaiah 2, talking about the same coming event, which is part of a block of prophecy where those wholly ruined aren’t annihilated, but eventually repent of their sins and go to the “survivors” of God’s wrath to be reconciled to God, which God accepts washing them clean with spirit and with fire. (Isaiah 4.) Again, far from a result of hopeless annihilation.
2 Thess 1 is actually one of my scriptural testimonies for universal salvation.
Which need not mean anything more specific than post-mortem punishment. The term translated “soul” there refers to what we might call the physical soul, the psukos, not the spiritual soul, or pneumas. (Although admittedly the former is sometimes used in ways analogous to the latter.) The same term is used when talking about the bod
The passages I have in mind when I recall the possibility of body and soul being destroyed, involve comparisons of God’s power to those of creaturely enemies, not comparisons with having eternal life. Do not fear those who can only destroy the body and thereafter have nothing more they can do, but fear the one Who can destroy both body and soul in hades/sheol, yes fear Him! (But also in the same sermon, do not fear Him, for you are worth more than the flowers which are here today and tomorrow thrown into the fire. That’s practically testimony against hopeless annihilation: God values people more than that. Nevertheless, if it comes to a fear for our lives, and only to that, we would still do better to fear God more.)
Since the term for destruction there can and does refer to people who are afterward saved (such as in the parable of the prodigal son), and is actually weaker than the related term Paul uses at 2 Thess 1:9, which we know from his other usage at 1 Cor 5:5 he means hopeful punishment by, the term itself is no certain testimony to hopeless punishment of any kind.
Insofar as “perishing” being contrasted to having eonian life, people and their souls are “perishing” now. It is in fact just the same word as being “lost” (which is hardly a hopeless condition), or “destroy” (also demonstrably not a hopeless condition), except in middle-voice form.
I don’t usually appeal to such an explanation, only if the local contexts demonstrably point that way. When there are no specific contexts, the terms for destruction themselves feature such a wide degree of usage where there are contexts, that their meaning should either be left indeterminate or assessed by extended contexts elsewhere. Which is probably why you hear universalists reading the belief into the term usage; annihilationists and ECT proponents are (in principle) doing the same thing, from meanings they think they’ve established elsewhere. They aren’t necessarily doing the wrong thing in principle, depending on their rationales elsewhere; universalists aren’t necessarily either, by the same token. (But being very picky I try not to read the belief in from extended contexts, preferring an indeterminate generalization where local contexts are lacking. I don’t have to specify the specifics of what “zorching” means, to recognize its general thrust of meaning. )