Well we've got the easy question out of the way...sort of. The second question, "if hell exists, then who's going?" is a bit trickier. Let me begin with this disclaimer: I am in no position to speculate on the eternal whereabouts of any particular soul. And, by the way, neither is anyone else. None of us can say with any degree of certainty that any specific person is in hell. No not even that one. That said, I think Jesus does give us some indication of what kind of person, or lifestyle should be cause for concern.
For my money, nothing beats the parable of the prodigal son. It's found in Luke 15, so go read it if you haven't yet. The cliff notes of it is that there are two sons and one righteous father. The younger son takes his inheritance in advance and blows it on women and whiskey, wakes up in a pig-sty, and comes crawling home to the compassionate and unqualified embrace of his father. The elder son stayed by the father's side, carried out his duties, and didn't spend nary-a-night with a pig.
The father throws a party to celebrate the return of his youngest, which I presume to be symbolic of heaven. Read the whole chapter and you'll see why. The elder son is envious of this extravagance, and refuses to go in.
OK, here's my take on all of this....The younger sons fault is that he didn't yet understand the fathers love. He thought there was something better out there. Eventually, he realized that he was horribly wrong. The elder son was content to remain in the fathers loving presence. His fault was that he wanted to keep his fathers love to himself.
The most scandalous, and terrifying truth of this parable is that the person on the outside is there by his own choice! The father was begging him to come in and he refused to! It should scare the crap out of all of us who are Christian by birth that the purest, and best behaved of these two brothers couldn't stomach the goodness of the father. The point that Jesus is revealing is clear...all rebellion is destructive, but the number one risk factor for eternal damnation is too much religion. Think about it. Break it down all you want to. There's only one reason the elder son missed out. He simply didn't like who else was on the guest list. Decades of duty-bound service had hardened his heart, and convinced him of his own worthiness. It was no longer enough that he got in. He had to control who else got in too.
In the end, the father was better than either son realized. The rebellious son came to his senses ( v. 17 ). The elder son never did. The moral: self-indulgence and self-righteousness are both sinful, but self-righteousness sets the deeper stain. God help us.