(Rev 2:11 ESV) 11 He who has an ear, let him hear what the Spirit says to the churches. The one who conquers will not be hurt by the second death.
(Rev 20:6 ESV) 6 Blessed and holy is the one who shares in the first resurrection! Over such the second death has no power, but they will be priests of God and of Christ, and they will reign with him for a thousand years.
(Rev 20:14-15 ESV) 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.
(Rev 21:7-8 ESV) 7 “The one who conquers will have this heritage, and I will be his God and he will be my son. 8 But as for the cowardly, the faithless, the detestable, as for murderers, the sexually immoral, sorcerers, idolaters, and all liars, their portion will be in the lake that burns with fire and sulfur, which is the second death.”
The “second death” is death suffered by the damned in the afterlife. They are burned in the lake of fire and sulfur, but nothing says they’ll live forever in torment. Rather, they die a horrible, painful death.
I mean, how does “death” (thanatos) come to mean “not die”? No, the damned die in eternity, but they suffer in their dying in proportion to their sinfulness — with God’s perfect justice.
The image is taken from the OT —
(Isa 66:22-24 ESV) 22 “For as the new heavens and the new earth that I make shall remain before me, says the LORD, so shall your offspring and your name remain. 23 From new moon to new moon, and from Sabbath to Sabbath, all flesh shall come to worship before me, declares the LORD.
24 “And they shall go out and look on the dead bodies of the men who have rebelled against me. For their worm shall not die, their fire shall not be quenched, and they shall be an abhorrence to all flesh.”
This is the end of Isaiah. It speaks of a fire that “shall not be quenched” — will not be put out — in which the damned are found as “dead bodies” or “corpses” (NIV). The damned die. The fire is not quenchable — meaning it will not fail in its purpose to destroy the damned utterly, so that there is no hope of resurrection, immortality, or eternal life for the damned. None. But they die. Isaiah couldn’t be more clear.
Daniel tells us —
(Dan 12:2-3 ESV) 2 And many of those who sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt. 3 And those who are wise shall shine like the brightness of the sky above; and those who turn many to righteousness, like the stars forever and ever.
The saved receive “everlasting life.” The damned receive “shame and everlasting contempt.” But they don’t live forever. Rather, in an honor/shame culture, they receive the worst possible fate — unending shame. But just as Isaiah 66:24 teaches, their shame lasts for all time — surviving their deaths.
(Job 8:20-22 ESV) 20 “Behold, God will not reject a blameless man, nor take the hand of evildoers. 21 He will yet fill your mouth with laughter, and your lips with shouting. 22 Those who hate you will be clothed with shame, and the tent of the wicked will be no more.”
Again, we see in Job that the evildoer suffers shame but “the tent of the wicked will be no more.” He will cease to exist.