Adam's death, the first death, was a UNIVERSAL, corporate judgement for a single sin. The plants, the animals, all human beings, the ground... the very matter of the universe itself was affected. Even the people who never ate of the fruit that Adam ate experienced that judgement of death.
Rom 5:12-14 NASB 12 Therefore, just as through one man sin entered into the world, and death through sin, and so death spread to all men, because all sinned-- 13 for until the Law sin was in the world, but sin is not imputed when there is no law. 14 Nevertheless death reigned from Adam until Moses, even over those who had not sinned in the likeness of the offense of Adam, who is a type of Him who was to come.
The second death is an INDIVIDUAL judgement. The first death was just and true because all people sin. The Law came so that there would be a measure whereby someone could be declared righteous. Without The Law, there was no way to measure sin. It took someone coming to earth and living a perfect, sinless life to make that first judgment (death) unjust. That necessitates a repeal of the first judgment (death), in lieu of individual judgments.
[1Co 15:21-22, 26 NASB] 21 For since by a man [came] death, by a man also [came] the resurrection of the dead. 22 For as in Adam all die, so also in Christ all will be made alive. ... 26 The last enemy that will be abolished is death.
[2Ti 1:10 NASB] 10 but now has been revealed by the appearing of our Savior Christ Jesus, who abolished death and brought life and immortality to light through the gospel,
Adam's universal judgment was death. Because of Christ's appearing (not his death on the cross), Adam's death judgment must be repealed. We are not saved by Christ from the first judgement, but from the second. But the gift of grace doesn't cover that one sin of Adam, it covers many sins. In other words, Christ's redemption doesn't cover Adam's one universal sin, it covers each of on an individual basis... this is why each of us must qualify for forgiveness individually.
[Rom 5:16 NASB] 16 The gift is not like [that which came] through the one who sinned; for on the one hand the judgment [arose] from one [transgression] resulting in condemnation, but on the other hand the free gift [arose] from many transgressions resulting in justification.
Rev 20:11-15 NASB 11 Then I saw a great white throne and Him who sat upon it, from whose presence earth and heaven fled away, and no place was found for them. 12 And I saw the dead, the great and the small, standing before the throne, and books were opened; and another book was opened, which is [the book] of life; and the dead were judged from the things which were written in the books, according to their deeds. 13 And the sea gave up the dead which were in it, and death and Hades gave up the dead which were in them; and they were judged, every one [of them] according to their deeds. 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 second death, unlike Adam's first universal death, is an individual judgement. There is no escape for those who are individually judged with the second death.