It is as if a king had sent you to a country to carry out one special, specific task. You go to the country and you perform a hundred other tasks, but if you have not performed the task you were sent for, it is as if you have done nothing at all. So people have come into the world for particular tasks, and that is our purpose. If we don't perform it, we will have done nothing.
RumiDo thou smile like the rose at loss and gain; For the rose, though its petals be torn asunder, Still smiles on, and it is never cast down.
Rumi