What is the logic in "life after death"?

[Godscreated]

OK I know that you'll say that logic and religion don't go together but there must be something that religious people use to rationalize this very central reason why most of them bother with religion.

Logic and Christianity go hand in hand. It's those who have been blinded by their hero's who believe there is no logic in Christianity. Just look at the atheist here site all the time, it's the same ones over and over. Christianity only becomes a bother when Christians do not want to follow God's will completely.

So, what would be the point of creating this world only to test people here to see if they'll go to heaven or hell? Looking at popular belief (and not strictly the scriptures) of who goes where : the killers, thieves, gluttonous and rapists get denied of heaven and are sentenced to hell - but why?

This world was and never has been a testing ground for salvation. You have missed the reason God made this world exist, it's called love and because it came about from God his Providence reigns over all of it, you nor any one else has a say in this. When we choose Jesus as our savior we are then shown why God's Providence reigns, it's part of growing in a relationship with Him.
Popular belief is where people get themselves into trouble, people want to be lazy instead of studying and searching the Bible, popular belief saves no one, scripture is plain on how salvation is obtained. All those things you mentioned are forgivable sins in this life as long as we have Jesus as Savior.

Because when you get to heaven you are immortal and if you can't die - nobody can kill you; if everybody has everything - why bother stealing?; if you don't have to eat because you're a ghost and already dead - so what if you were gluttonous?; and if everybody is lacking genitals then nobody can rape anybody.

You start out the above with those in heaven as immortals then you go on to say those in heaven are dead ghosts, seems to me you"re so confused about every aspect of Christianity it's no wonder you can't figure anything out. Who says we will have things that could be stolen, scripture teaches us to lay up our treasures in heaven where they can never be stolen. Who says we want eat, we're going to have physical bodies as Jesus does and He ate with the disciples. We are told we want have the same relationship with our wives as we did here on earth, heaven will be a different and better way of life.

What am I missing here? Does anyone have an answer to this?

You are missing the entire point of Jesus and the forgiveness that is necessary to be redeemed to enter heaven. You have made this conclusion clear by what you have posted above. If you are not reconciled to God through your own choice you want see heaven, that's as plain as I can put it and the NT scriptures teach this as plain as day. Sorry if this isn't what you want to hear but, it's the simple an absolute truth of it.

GC