Revelation 2:11 He who has an ear, let him hear what the Spirit says to the churches; He who overcomes shall not be hurt of the second death.
6] Blessed and holy is he who has part in the first resurrection: on such the second death has no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years.
14] And death and hell were cast into the lake of fire. This is the second death.
Revelation 21:8 But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burns with fire and brimstone: which is the second death.