'Second Death' in the Bible

He who has an ear, let him hear what the Spirit says to the assemblies. He who overcomes won't be harmed by the second death.

Blessed and holy is he who has part in the first resurrection. Over these, the second death has no power, but they will be priests of God and of Christ, and will reign with him one thousand years.

Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire.

But for the cowardly, unbelieving, sinners, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars, their part is in the lake that burns with fire and sulfur, which is the second death."