In most Protestant traditions, hell is the place created by God for the punishment of the devil and fallen angels (cf. Matthew 25:41), and those whose names are not written in the book of life (cf. Revelation 20:15). It is the final destiny of every person who does not receive salvation, where they will be punished for their sins. People will be consigned to hell after the last judgment.
One historic Protestant view of hell is expressed in the Westminster Confession (1646): “but the wicked, who know not God, and obey not the gospel of Jesus Christ, shall be cast into eternal torments, and punished with everlasting destruction from the presence of the Lord, and from the glory of his power. " (Chapter XXXIII, of the Last Judgment) According to the Alliance Commission on Unity & Truth among Evangelicals (ACUTE) the majority of Protestants have held that hell will be a place of unending conscious torment, both physical and spiritual, although some recent writers such as Anglo-Catholic C.S. Lewis and J.P. Moreland have cast hell in terms of "eternal separation" from God. Certain biblical texts have led some theologians to the conclusion that punishment in hell, though eternal and irrevocable, will be proportional to the deeds of each soul (e.g., Matthew 10:15, Luke 12:46-48) Another area of debate is the fate of the nonevangelized (i.e.,those who have never had an opportunity to hear the Christian gospel), those who die in infancy, and the mentally disabled. According to ACUTE some Protestants agree with Augustine that people in these categories will be damned to hell for original sin, while others believe that God will make an exception in these cases.
A minority of Protestants believe in the doctrine of conditional immortality, which teaches that those sent to hell will not experience eternal conscious punishment, but instead will be extinguished or annihilated after a period of "limited conscious punishment". Prominent evangelical theologians who have adopted conditionalist beliefs include John Wenham, Edward Fudge, Clark Pinnock and John Stott (although the last has described himself as an "agnostic" on the issue of annihilationism). Conditionalists typically reject the traditional concept of the immortality of the soul.
The Seventh-day Adventist Church, Jehovah's Witnesses and Christadelphians teach the annihilationist viewpoint. Wikipedia
The following is from the 7th Day Adventists web site Amazing facts.com:
Matthew 25:41 speaks of "everlasting fire" for the wicked. Does it go out? Yes, according to the Bible, it does. We must let the Bible explain itself. Sodom and Gomorrah were destroyed with everlasting, or eternal, fire (Jude 7), and that fire turned them "into ashes" as a warning to "those that after should live ungodly," 2 Peter 2:6. These cities are not burning today. The fire went out after everything was burned out. Likewise, everlasting fire will go out after it has turned the wicked to ashes (Malachi 4:3). The effects of the fire are everlasting, but not the burning itself.
The Bible tells us that "the wages of sin is" not eternal life in hellfire, but "death" (Romans 6:23), the same penalty God assured Adam and Eve would be theirs if they ate the forbidden fruit.
Ezekiel states clearly that "the soul that sinneth, it shall die" (Ezekiel 18:4), and a plethora of other Bible verses and passages endorse this position. The prophet Malachi wrote that sinners would burn up as "stubble" and would become "ashes under the soles" of the feet of the redeemed (Malachi 4:1, 3). Even the final fate of Satan is explicitly pronounced in Ezekiel 28:18, where the Bible says that the enemy of souls will be reduced to ashes upon the "earth."
Compare that with Psalm 37:10 ("For yet a little while, and the wicked shall not be"), Psalm 68:2 ("as wax melteth before the fire, so let the wicked perish at the presence of God"), and other similar verses. Soon you get a clear picture that the purpose of the fires of hell is to eradicate sin and to expunge the universe of its awful presence.
Interestingly, it was the devil who was first to suggest that sinners would not die (Genesis 3: 4). A hell where sinners never perish would prove the devil right and would make God, who told Eve she would "surely die" as a result of transgression (Genesis 2:17), a liar.
Now let’s hear from the Jehovah’s Witnesses web site JW.com: Many people believe in a fiery hell... However, the Bible teaches otherwise. Those in hell are unconscious and so cannot feel pain. “There is no work nor devising nor knowledge nor wisdom in Sheol.”--Ecclesiastes 9:10 (Sorry, the author of this blog can’t resist - The JWs have “Sheol” mixed up with the final “hell ,or second death – the lake of fire!) Death, not torment in a fiery hell, is the penalty for sin. “He who has died has been acquitted from his sin.”--Romans 6:7. (Sorry again. Paul was not speaking of literal death of the body. He was speaking of the death of the old self when being born into Christ as a new creature!) Eternal torment would violate God’s justice. (Deuteronomy 32:4) When the first man, Adam, sinned, God told him that his punishment would simply be to pass out of existence: “Dust you are and to dust you will return. –Genesis 3:19 God would have been lying if he were actually sending Adam to a fiery hell. (Sorry once again. Here, God was talking about the physical body. Returning to “dust” has nothing to do with hell.)
Back to Wikipedia to see what the Church of Jesus Christ of Latter Day Saints believes:
The Church of Jesus Christ of Latter Day Saints (LDS Church) teaches that the word "hell" is used scripturally in at least two senses. The first is a place commonly called Spirit Prison which is a state of punishment for those who reject Christ and his Atonement. This is understood to be a temporary state in which the spirits of deceased persons will be taught the gospel and have an opportunity to repent and accept ordinances of salvation. Mormons teach that it was for this purpose that Christ visited the Spirit World after his crucifixion (1 Peter 3:19–20, 1 Peter 4:5–6). Modern-day revelation clarifies that while there, Christ began the work of salvation for the dead by commissioning spirits of the righteous to teach the gospel to those who didn't have the opportunity to receive it while on earth.
Latter-day Saints believe that righteous people will rise in a "first resurrection" and live with Christ on earth after His return. After the 1000 years known as the Millennium, the individuals in spirit prison who chose not to accept the gospel and repent will also be resurrected and receive an immortal physical body, which is referred to as the "second resurrection". At these appointed times of resurrection, "death and hell" will deliver up the dead that are in them to be judged according to their works (Revelations 20:13), at which point all but the sons of perdition will receive a degree of glory, which Peter compared to the glory of the sun, moon, and stars (1 Corinthians 15:41). The LDS Church explains biblical descriptions of hell being "eternal" or "endless" punishment as being descriptive of their infliction by God rather than an unending temporal period. Latter-day Saint scripture quotes God as telling church founder Joseph Smith: "I am endless, and the punishment which is given from my hand is endless punishment, for Endless is my name. Wherefore—Eternal punishment is God's punishment. Endless punishment is God's punishment.
Latter-day Saints also believe in a more permanent concept of hell, commonly referred to as outer darkness. It is said that very few people who have lived on the earth will be consigned to this hell, but Latter-day Saint scripture suggests that at least Cain will be present. Other mortals who during their lifetime become sons of perdition, those who commit the unpardonable sin, will be consigned to outer darkness. It is taught that the unpardonable sin is committed by those who "deny the Son after the Father has revealed him". However, the vast majority of residents of outer darkness will be the "devil and his angels ... the third part of the hosts of heaven" who in the pre-existence followed Lucifer and never received a mortal body. The residents of outer darkness are the only children of God that will not receive one of three kingdoms of glory at the Last Judgment.
It is unclear whether those in outer darkness will ultimately be redeemed. Of outer darkness and the sons of perdition, Latter-day Saint scripture states that "the end thereof, neither the place thereof, nor their torment, no man knows; Neither was it revealed, neither is, neither will be revealed unto man, except to them who are made partakers thereof". The scripture asserts that those who are consigned to this state will be aware of its duration and limitations.
Also according to Wikipedia, Christian Science defines "hell" as follows: "Mortal belief; error; lust; remorse; hatred; revenge; sin; sickness; death; suffering and self-destruction; self-imposed agony; effects of sin; that which 'worketh abomination or maketh a lie. '" (Science and Health with Key to the Scripture by Mary Baker Eddy, 588: 1-4.)
Furthermore, The Unity Church of Charles Fillmore considers the concept of everlasting physical Hell to be false doctrine and contradictory to that reported by John the Evangelist. Wikipedia
Unitarian Universalists stir in a whole hodgepodge of beliefs, religions and philosophies under their name. So it can easily be concluded that those who feel the need for salvation and an afterlife believe there are many paths to them, even through the death and resurrection of Christ. There exist “Diverse beliefs, but most believe that heaven and hell are not places but are symbolic. Some believe heaven and hell are states of consciousness either in life or continuing after death; some believe in reincarnation; some believe that afterlife is nonexistent or not known or not important, as actions in life are all that matter.” beliefnet.com
There are many, many other denominational viewpoints on this subject. I have only chosen the most mainstream of them. Even from church to church within a denomination you may well find differences of opinion. And even within a single church building differences. Finally, it is important to note that there is a quickly growing ideal in several churches that are beginning to deny the existence of a future “hell”, “lake of fire”, whatever you want to call it, when the Bible is very clear that there shall be such a thing as eternal condemnation. Though we do not know what that may yet be, we can be sure it will be.