How is it that one is saved from hell? Well, it looks like Jesus told us exactly how, and all you need are some surgical instruments:
Wherefore if thy hand or thy foot offend thee, cut them off, and cast them from thee: it is better for thee to enter into life halt or maimed, rather than having two hands or two feet to be cast into everlasting fire. And if thine eye offend thee, pluck it out, and cast it from thee: it is better for thee to enter into life with one eye, rather than having two eyes to be cast into hell fire. – Matthew 18:8-9
And if thy hand offend thee, cut it off: it is better for thee to enter into life maimed, than having two hands to go into hell, into the fire that never shall be quenched: Where their worm dieth not, and the fire is not quenched. And if thy foot offend thee, cut it off: it is better for thee to enter halt into life, than having two feet to be cast into hell, into the fire that never shall be quenched: Where their worm dieth not, and the fire is not quenched. And if thine eye offend thee, pluck it out: it is better for thee to enter into the kingdom of God with one eye, than having two eyes to be cast into hell fire: Where their worm dieth not, and the fire is not quenched. – Mark 9:43-48
It should be pretty obvious that basically no Infernalist (someone who believes in never-ending torment for people who die as non-Christians) or Annihilationist (someone who believes that people who die as non-Christians will cease to exist forever in the end) actually interprets these two parallel passages literally. In fact, I doubt you personally know a single Christian who both believes that these passages prove never-ending punishment and who has also actually mutilated or amputated parts of their body in order to avoid going to hell, which means they aren’t taking the way to avoid being cast into “everlasting fire” or “hell fire” particularly literally. And if one isn’t going to interpret the method of avoiding the punishment literally, there’s zero reason to take the punishment itself (or the duration of the punishment, for that matter) in those passages literally either. In fact, it would be entirely inconsistent to do so.
This is very simple. If the parts about “everlasting fire” and “hell” in those passages are literal, then the part about bodily mutilation has to be as well, and if it is, that means salvation isn’t only attainable by “believing the Gospel,” but is also possible to attain simply by mutilating or amputating parts of your body.
It also helps to realize that the passages in question are references to a prophecy of Isaiah about a time in the future that Jesus was pointing back to when He used the word, a prophecy that referred to carcases, meaning dead bodies, by the way, and not to anyone who is alive or consciously suffering, at least if we’re taking the passage in Isaiah literally, so there’s once again zero reason to believe these passages are talking about anybody suffering forever, in fire or otherwise.
So what do these passages mean? I’m not going to get into that here (although I have elsewhere on this website). The point I’m making is simply what they don’t mean. If you truly are curious, though, I did write about it here.