First of all, everybody has a good reason to thrive! Perhaps the reason is not obvious to the person in that moment.

Think about what you love or loved doing in your life, and find an opportunity to do it again. Take action and do it!

If you are seriously depressed, then consult a healthcare practioneer. If there is something going on in your life that constantly drags you down, get some support to eliminate this element from your life.

When the negative elements are eliminated, and the positive elements find support, it will become easier for you to see the reason why you are on earth. If you still don't see it, get some professional help making it obvious to you.