There are three different concepts that are translated "Hell" in various Bibles, which has caused a lot of confusion.
Sheol (in Greek Hades) is the common Grave of humankind. As Jesus himself demonstrated, one can get resurrected from the grave. John 5:28-29, 1 Corinthians 15:3-5
Gehenna (which Jesus referred to in his sermon on the mount) is the second death, eternal death that is due to unrepentant sin, which is mentioned in Revelation 20:13-15 and Revelation 21:8.
Tartarus is the prison of the angels who sinned in Noah's day 2 Peter 2:4
Information on how hell was redefined from pagan teachings:
Various nominal Christian groups believe in the Greek version of hell. The Bible is not consistent with those ideas.
The Bible says that the wages sin pays is death. Jesus spoke of Gehenna, which is eternal death, which many Bibles erroneously translate as hellfire.
A word used in the King James Version (as well as in the Catholic Douay Version and most older translations) to translate the Hebrew sheʼohlʹ and the Greek haiʹdes. In the King James Version the word “hell” is rendered from sheʼohlʹ 31 times and from haiʹdes 10 times. This version is not consistent, however, since sheʼohlʹ is also translated 31 times “grave” and 3 times “pit.” In the Catholic Douay Version sheʼohlʹ is rendered “hell” 64 times, “pit” once, and “death” once.
But the original English word "hell" had nothing to do with eternal torment.
It is, in fact, because of the way that the word “hell” is understood today that it is such an unsatisfactory translation of these original Bible words.
Webster’s Third New International Dictionary, unabridged, under “Hell” says: “fr[om] . . . helan to conceal.” The word “hell” thus originally conveyed no thought of heat or torment but simply of a ‘covered over or concealed place.’
In the old English dialect the expression “helling potatoes” meant, not to roast them, but simply to place the potatoes in the ground or in a cellar.
The meaning given today to the word “hell” is that portrayed in Dante’s Divine Comedy and Milton’s Paradise Lost, which meaning is completely foreign to the original definition of the word. The idea of a “hell” of fiery torment, however, dates back long before Dante or Milton.
The Grolier Universal Encyclopedia (1971, Vol. 9, p. 205) under “Hell” says: “Hindus and Buddhists regard hell as a place of spiritual cleansing and final restoration. Islamic tradition considers it as a place of everlasting punishment.” The idea of suffering after death is found among the pagan religious teachings of ancient peoples in Babylon and Egypt. Babylonian and Assyrian beliefs depicted the “nether world . . . as a place full of horrors, . . . presided over by gods and demons of great strength and fierceness.”
Although ancient Egyptian religious texts do not teach that the burning of any individual victim would go on forever, they do portray the “Other World” as featuring “pits of fire” for “the damned.”—The Religion of Babylonia and Assyria, by Morris Jastrow, Jr., 1898, p. 581; The Book of the Dead, with introduction by E. Wallis Budge, 1960, pp. 135, 144, 149, 151, 153, 161, 200.
The punishment for sin is the same as in the Garden of Eden. DEATH. Genesis 2:16-17 Faith in Jesus and repentance with changing our lives in harmony with his teachings of truth is the way to eternal life.
16 “For God loved the world so much that he gave his only-begotten Son, so that everyone exercising faith in him might not be destroyed (or, perish) but have everlasting life."
23 For the wages sin pays is death, but the gift God gives is everlasting life by Christ Jesus our Lord.