These questions are hypothetical, and may have no answer that is humanly obtainable. It is interesting to think about such things though, so I present them for discussion.
1) If one of your skin cells die, then you are obviously still 'alive'. I'm sure that many people believe that even if your entire body died, with only your brain surviving (and kept on a form of life support), then the 'you' is still alive. Your soul is not yet on its journey into the afterlife, since your brain is fully functional (so I believe). But, the question is: how many of your brain cells have to die before the soul crosses over? Might the soul still be retained in this reality if even a single brain cell is kept alive? I'm sure it's a difficult question.
2) Perhaps some of you have heard of "Multiple Personality Disorder", the condition in which one person seems to manifest two or more individual personalities in the same body. Let's say there is a person with this condition who has the personality of a saved Christian, but also has the alternate personality of an aethiest. When this person dies, do they go to Heaven or Hell? Does their soul 'split in two', with each personality going to the appropriate location?
3) When the end-times come, those who accept the Mark of the Beast will be damned to Hell. But what about now? What if someone were to tatoo themselves with the Mark of the Beast in the current day and age? Would they too be damned?
I wish I could answer your questions but I don't think I can.
3. I don't think the "mark" of the beast will come in a tatoo form, therefore I think it's impossible to do that today. If one could, well, I guess if they repented for having done it before the beast came, I would think they could still go to heaven, because it was a faux mark to begin with.
2. MPI.......I don't think people are born with a MP. So, if this person was saved before the 2nd personality cropped up, I believe they would go to heaven. If the athiest personality is the true personality. Know what? These kinds of questions drive me nuts.
Know why? I'm guilty of asking them myself. I think only God would know and it's probably dependent.
1. It might, and it's also very frightening to think about. I don't see how just one brain cell might be kept alive, though. Besides, aren't brain cells different from skin cells?
We could go very deep with these questions, and it would be endless, because any answer leads to another like question. Sometimes it's fun though, if one can discipline themselves enough to stop thinking about it.
Grace and peace,
cris