DEATH IS A RETURN

Death is the wages of sin.
Death is not another form of life.
Death is the absence of life.
The word in the Bible most associated with “death” is “return”.
The spirit returns to God at death.
The body returns to dust.
The soul returns to the unseen.
Your question (“…if all men ARE saved, why does your god cast even ONE into the lake of fire?”) is one of distraction.
Christ died to save all.
But not everyone comes into salvation all at once. Salvation, in all that it means, must include salvation from death.
Yet, even the saved, at the moment, enter the death state. Peter, James, John, Paul… all dead.
So…If Peter, James, John, and Paul are “saved” why did they have to die? That is the essence of your question. All (or should I say ‘most’) can expect to enter into the first death. Many will enter into the second death. But not to worry… death is death. And the second death is not a challenge to God’s saving work in the cross of Christ.
Death (all death-including the 2nd death) is the last enemy God abolishes. The other enemies listed in the passage under discussion (I COR 15:20-28) are rule, authority and power.

After all… I COR 15:26’s prophetic word that death will be undone… is actually preceded by I COR 15:22 — For even as in Adam, all are dying, thus also in Christ shall all be vivified.

Do not think that John’s Book of Revelation is the final prophetic word on God’s eonian purpose. I COR 15:20-28 is far greater in scope than the book of Revelation.
When John closes the book of Revelation, rule, authority and power– and death— are still present. But Paul (In I COR 15:20-28) reveals to us a time beyond what John sees. A time when even Christ’s reign will end. And death, the last enemy is abolished.
Stacy, this is good news.

YOU SAID:
“The soul does not RETURN to the unseen…”

MY REPLY:
(Psa.9:17 and Acts 2:27,31)
GOD’S WORD SAYS…. “The wicked do turn back to Sheol (UNSEEN)…” –Psa.9:17

GOD’S WORD SAYS… “For Thou wilt not be forsaking my soul in the unseen…” ACTS 2:27

GOD’S WORD SAYS… “concerning the resurrection of the Christ, that He was neither forsaken in the unseen…” ACTS 2:31

AND FINALLY: FROM JOB:
For I know that Thou wilt return me to death. (Job 30:23 AV).
ETC.
SO, I say again, the word RETURN is the one word most associated with the idea of death… in the bible.

THE DEAD ARE DEAD. They are not still alive. Death is the opposite of life.
and according to I COR: 15:24-26… death is the last enemy to be abolished, therefore, all will be made alive… because death is abolished. And THEN God will be all in all.