No hope?

Hope never fails. We are called to be the salt and light of the world, and we should be the ones to offer support in other people's time of need, to care and to love, to bring them hope. But what if the situation which requires our help actually ends up pulling you down with it? I mean, lets say what happens if someone who has reached a point of desperation asked for your help, desperately in need of hope? And you know that the person has the potential to ruin and turn your life upside down (be it your studies, relationships etc). Ok, maybe I am passing judgement too early but assuming that's the case..

You have the right to be 'smart' and say no. Nothing will happen to you then.. I might probably have to think deeply and in a worst case scenario, the most I can probably offer is prayer for him.. But will you step forth and say yes? Suffering builds perseverance, perseverance character, and character hope. However, sometimes I tend to wonder whether we have a right to leave any room for selfishness in certain situations to safeguard our needs.. but wait, that means I am worrying already.. Worrying indicates lack of faith.. How much do you actually love that person? But what do you do then?