We can never build a permanent sense of our own worth if we base our worth on things that are bound to change. This is why Self-Esteem is a myth:
1) Self-esteem is based on what we do and how we behave.
If our worth is based on our performance or behavior, then we are bound to feel poorly about ourselves when our performance or behavior drops; and it will drop—it's human nature. We are more than what we do and how we behave.
2) Self-esteem is based on how we feel about ourselves.
Basing our worth on our emotions can never succeed, because emotions are fickle. Like clouds in the sky, they come and go according to the pressure in the air. Our emotions can also be false. We can feel like a "bad" person when that's absolutely not the case. We are more than how we feel about ourselves.
3) Self-esteem is based on what we think about ourselves.
While I believe self-evaluation is a positive tool for personal growth, we mustn't base our worth on our thoughts and evaluations. Most of us have flawed thoughts running through our minds all day long, and many times we don't even know they're there! We are definitely more than what we think about ourselves.
4) Self-esteem is based on how we're doing compared to others.
We don't just evaluate ourselves on how well we're doing compared to our own potential (which is healthy); with self-esteem, we compare ourselves to others. It's fine to compare to others at times if it helps us see something to work on or inspires us to grow, but usually comparing to others just makes us feel worse about ourselves. The truth is, no matter how great we are at any given thing, there will always be somebody smarter, faster, skinnier, braver, kinder, and more "talented". That's when the identity crisis hits. "I thought I was good at that, but now I'm not so sure." We absolutely cannot base our own worth on what others do or don't do.
5) Self-esteem is based entirely on judgments, whether from others or from ourselves.
And nothing good can come of that. We are certainly more than we or anyone else judges us to be.