Are you in love with someone that you can't be with? That you think that there's no possibility? ..
Why do you think that? Would you give up? If the answer is "yes".. why would you? Isn't it that you love him/her? So, why don't you fight? Just have faith, and hope. If he's/she's for you, you will be together in the right time.. if not, there's always someone out there for you, the right one, the one who will love you the way you do. But try it, because you just don't know what can happen..
And it's true that if you don't try you don't lose anything, but always remember that you can't win anything also.
There are many questions in this life, but every question has it's answer. Not everyone knows it, but you can go to find it by yourself.