Although the term is not found in the Hebrew Bible (the Canonical collection of Hebrew scriptures), Harry Sysling, in his study (1996) of Teḥiyyat ha-metim (Hebrew; "the resurrection of the dead") in the Palestinian Targums, identifies a consistent usage of the term "second death" in texts of the Second Temple period and early rabbinical writings. In most cases, the "second death" is identical with the judgment, following the resurrection, in Gehinnom at the Last Day.
Targum Isaiah has three occurrences. The first is 22:14, where the Aramaic paraphrases the Hebrew as "This sin will not be forgiven you until you die the second death."  The final two examples are from Targum Isaiah 65, which sets the scene for an apocalyptic final battle. Targum Isaiah 65:6 paraphrases the Hebrew in line with the interpretation of the penultimate verse of the Hebrew Isaiah found in the Gospel of Mark, where "their worm does not die" is equated with Gehinnom. Here both Targum Isaiah and Gospel of Mark supply the term "Gehinnom", where Hebrew Isaiah simply concludes with the heaps of corpses following the last battle where "their worm does not die", making no further eschatological extension into resurrection and judgment.
Targum Jeremiah 51:17 has the Aramaic "they shall die the second death and not live in the world to come", which appears to depart from the other Targum uses in not being explicit that the second death is after resurrection but may instead be an exclusion from resurrection.
The majority reading of Targum Psalm 49:11 has the Aramaic translation "For the wise see that the evildoers are judged in Gehinnom". However, several manuscripts, including Paris No.10, Montefiore No.7, and Targum of Salomos 113 have the variant Aramaic translation "He sees men wise in wickedness, who die a second death, and are judged in Gehinnom".
The term "second death" occurs four times in the New Testament, specifically in Revelation 2:11, 20:6, 20:14 and 21:8. According to Revelation 2:11 and 20:6, those who overcome the devil's tribulation are holy and have a part in the first resurrection will not experience the second death. Revelation 20:14 and 21:8 then provides parallelism between the second death and the lake of fire. In Revelation 21:8 we read: "[A]s for the cowardly, the faithless, the polluted, the murderers, the fornicators, the sorcerers, the idolaters, and all liars, their place will be in the lake that burns with fire and sulfur, which is the second death."
One interpretation states that when people are saved, they are not subject to the second death. They only die of the earthly first death. However, an unsaved person will experience two deaths: the first, being a physical death; and the second being a spiritual death, i.e., separation from God. resurrection. The second death is usually interpreted as an everlasting torment or everlasting destruction. The traditional view of the everlasting torment was elucidated by Lactantius:
We term that punishment the second death, which is itself also perpetual, as is immortality. We thus define the first death: Death is the dissolution of the nature of living beings, or thus: Death is the separation of body and soul. But we thus define the second death: Death is the suffering of eternal pain, or thus: Death is the condemnation of souls for their deserts to eternal punishments.
Christian universalists, who believe all will be reconciled to God, reject the notion of endless torment and therefore offer different interpretations. For example, Gregory of Nyssa understood the second death as a cleansing, albeit a painful process. He wrote that "those still living in the flesh just as much as they can separate and free themselves in a way from its attachments by virtuous conduct, in order that after death they may not need a second death to cleanse them from the remnants that are owing to this cement of the flesh". Annihilationists and conditionalists, including all Seventh-day Adventists and Jehovah's Witnesses, and others in many denominations, also oppose the idea of eternal suffering, but believe that the second death is an actual second death and that the bodies and souls condemned to it after the final judgment will be utterly destroyed.
The Mandaeans, a Gnostic religion, believe that the souls which could not be purified inside of demon Ur would get destroyed along with him at the end of days, so they die the second death.
- Harry Sysling Teḥiyyat ha-metim: the resurrection of the dead in the Palestinian Targums p222 1996 -"Here the second death is identical with the judgment in Gehinnom. The wicked will perish and their riches will be given to... The second death in the Apocalypse In the Apocalypse of John, the second death is mentioned several times....
- Sysling, p220
- Martin McNamara, Targum and Testament Revisited: Aramaic paraphrases of the Hebrew p.226 2010 - 359
- Sysling Teḥiyyat ha-metim: the resurrection of the dead in the Palestinian Targums p221 1996
- Israel Abrahams Studies in Pharisaism and the Gospels Page 44 "Qimhi's interpretation that the Second Death refers to the "death of the soul in the world to come" cannot be accepted without qualification. For in its paraphrase of Isaiah lxv. 6 the Targum uses the expression: "I will deliver."
- Maimonides’ Introduction to Perek Helek, publ. and transl. by Maimonides Heritage Center, p. 22-23.
- "Divine Institutes, Book II". Newadvent.org. Retrieved 6 July 2019.
- "On the Soul and the Resurrection (St. Gregory of Nyssa)". Newadvent.org. Retrieved 6 July 2019. CS1 maint: discouraged parameter (link)
- Kurt Rudolph: Theogonie. Kosmonogie und Anthropogonie in den mandäischen Schriften. Eine literarkritische und traditionsgeschichtliche Untersuchung, Göttingen 1965, p. 241.
- Ginza. Der Schatz oder das große Buch der Mandäer, ed. and transl. by Mark Lidzbarski, Quellen der Religionsgeschichte vol. 13, Göttingen 1925, p. 203.
- Ginza, ed. and transl. by Lidzbarski, p. 321.