Jesus never said "un-born", you did. Jesus ONLY says "born again". That's the only analogy He uses here. You are the one stretching this analogy to illogicality.
Because Jesus uses the analogy of birth to show a spiritual truth, doesn't mean that every aspect of birth is included in it.
Obviously he can, you "changed" into a "new creation" through faith, correct? If you lose this faith, you will REVERT back into your old self. It is through faith, an action, that you are saved, if you lose this faith, you will lose your salvation. Sounds pretty logical to me, friend.
Really? If a person backslides, he is what, Grappler? "Never saved in the first place", right? And how do you know this? Isn't it because of his OUTWARD ACTIONS? When you say this, are you "judging men's hearts"? A little more logic and a little less drama please.
How do you know that they were even a new-creature in Christ to begin with?
The same way you judge that he was "never saved in the first place", by his outward actions. According to you, James 2 teaches this exact doctrine, that we can see a man's "true faith" by his actions. A man can "show" his justification by what he does, the same way he can show his loss of salvation by his actions.