When a person relies on others, he loses his sense of self. For example, he makes sure his views are aligned with those of his boss so that he’ll always be on good terms. He feels that he must make sure he’s always conforming if he wants to get a promotion.
A person with bitachon can always be himself; he never has to sell out on his beliefs. Following you true beliefs can never take away from your parnassah, because it comes straight from Hashem!
The fact is clear: It is impossible to add or detract – even a tiny amount – from what was decreed from you. You can be yourself and you will never lose.