Never give up on anybody. Miracles happen every day.
Of course, no, they don't happen every day. They hardly ever happen or never happen, depending on how you define miracle. Things that happen every day are not miracles, they are common. It's cheapening the word.
I did reply, though:
If god is almighty, pray for the convergence of the -1^n series, and see how it works. There is no god but math.
Which is quite a troll, even for my standards, but hard to argue with, I expect. This post is a more serious response to that original quote. And my response is, sometimes, you need to give up. Further, sometimes, not giving up is stupid, painful, dangerous and selfish.
People don't really change all that much. They do it very slowly, when they do. And you are not (usually) the other person's guardian. There comes a point in people's lifes where helping them hurts them. Or worse, hurts the one helping.
Consider an abusive partner. Why should you not give up? Why allow him/her to hurt you further, in hope for a future change? That is just stupid and...
- Because you are being hurt, either in body or in mind. And being hurt is, of course, bad. So why enable it? Why allow someone to cause you pain, just for his own sake? What are you telling that person? That you feel good about helping those who hurt you? That is...
- Because he may believe you. You are teaching that person that you feel good helping those who hurt you, and that makes you a better person, so he may just try to help you be much better by hurting you further. And really, if that's how you feel, you are being ...
- Because helping someone just to feel self-righteous and pious and good is a scam. Help because you make the other feel good, not because it feels good for you. I see people trapped in abusive relationships, almost screaming "See how good I am! See the pain I take for love!" which is both selfish and insane.
So, give up. Because the path of the righteous man is beset on all sides by the inequities of the selfish and the tyranny of evil men. Blessed is he who, in the name of charity and good will, shepherds the weak through the valley of darkness, for he is truly his brother's keeper and the finder of lost children. But enough is enough. And stupid is bad.