You're going to hate me for saying this, but my motto is 'every bad thing happens for a good reason'.
Of course I don't direct that at everyone because when someone is feeling down or hasn't experienced anything good for a while it's going to be empty words. It is really only a saying for myself that I TRY to go by. I look at some of the good things that have happened and when I backtrack on it, it all stemmed from something bad.
For example, I live on my own now. I have floorboards, something I've always wanted, I live in the exact neighbourhood I wanted, I have a bath, I have trees. I live in a neighbourhood of friendly people. I've lived here 5 years in December, the longest I've ever lived in a house.That's a big step up from moving house 13 times or living in a neighbourhood known for drugs and violence, or living with an abuser, or living with no furniture or bed to sleep on.
If my mother had not been so abusive or neglectful that I had to get the hell out of there, I would not live in this house or have the safety and stability I now have.

There is also going to America. That never would have happened if my mother had not been in an abusive relationship. If he hadn't been around I wouldn't have dropped out of school. If i hadn't dropped out of school I never would have started a job program. If I'd never started the job program I never would have started volunteering with an environmental organisation. And if I'd never stared volunteering with them, I never would have got a sponsorship to America for a month with my flights, food, transport and accommodation all paid for.

Of course those examples are a bit extreme, but do you see how this saying kind of fits for me? Sometimes it's the only thing I've got to live by, the only thing that's going through my head when I'm about to top myself- 'something God damn decent better come out of this if I stick around'.
Of course it's hard to think that way when you're feeling crappy, even I think it's a load of garbage when I feel that way.

I do think that people who aren't going through mental illnesses and have never experienced it can be very naive about it, so they say things intending to sound helpful and only make you feel worse. I tend not to rely on these people for help anymore.