How do you reassure someone who thinks that his life is useless?(Details inside )

A tiny bit unclear, could you rephrase?

Tell him he is alive and capable of helping another human being. Tell him to quit feeling sorry for himself and do something useful.

@jonsblond I doubt that telling someone “stop whining you lazy fuck” is in any way, shape, or form helpful.
The only real way to raise self esteem is to find him some activities that are rewarded with recognition.
Can be small things, like helping old or crippled people across the street, or helping them carry things.
Then you can proceed to getting him a place in a club, public radio/television, where he can help out and learn things at the same time.
Or a crafting club, where you build things.
Basically any creative club activity, where you gain recognition for the things he makes, learns how to make things, and find out what he likes. Then he can focus on that.
Maybe helping out in a soup kitchen or homeless shelter (though that might turn out counter productive.)

If his self worth is in question for lack of a profession, your task would seem simplified from the realization that it is about changing his perspective. Don’t fall into the impossible trap of thinking you have to prove him wrong. Ask him to consider the possibility that he might be wrong, then point out that if he matters to anyone or anything at all, he is useful. It takes more than a profession to gauge the value of a man.

I never thought I would write this- @ragingloli has the best advice.

“Self -esteem” is not built on someone’s profession or job, it is developed on how much we care for and are involved with other people. The best way to improve one’s opinion of oneself is to not worry about oneself but to help someone else who needs a hand.

Volunteer, help out at church, or a soup kitchen, or a homeless shelter. All on had to do is say, “what can I do to help?”; before you know it the person will be contributing.

We all are presented with options and opportunities to make the world ( and ourselves) better. And many of them can be done for free.
If he takes a walk carrying a plastic trash bag he can clean up a section of a sidewalk. He can focus on making himself healthier. Virtually everything in life is better when we are in shape. Our minds get clearer, our immune system gets stronger, our breathing better.
Investing in ourselves is one of the best ways to increase our own self-worth.

@ragingloli- that’s not what I fucking said

@jonsblond if the rager of a loli said you said it, then you said it. :) ;)

I like to think of people as cells in the human body. Only we are each individual cells in the planet. We each serve a purpose. Some of us are like skin cells. Individually we may not do much but we control and protect the body. It may not be as glorious as brain cells or reproductive organs or white cells that attack invaders, but we help to hold everything together and in. So equally important. So long as you aren’t a cancer cell, you are good. Hell. Even fat cells serve a purpose.Sometimes by simply existing and leaving ourselves open to do good work when needed gives us purpose for being. I’m nothing to write about. No awe aspiring career. But I try to give comfort when needed, help when I’m able to either physically or emotionally. You never know what little thing you may say or do that helps someone get through life or maybe encourage someone to take a chance and do something awesome that will help others. A doctor may cure some people, but nurses, wash and tend their physical and emotional wounds and help sick people not feel forgotten or useless.