My God, the soul You have placed within me is pure (Siddur).
As we all know, self-esteem is essential for optimum mental health, and a lack of self-esteem can result in any of many emotional problems. Many of us don't know, however, that self-esteem is not at all antithetical to humility.
Self-esteem comes from a sense that one is competent and worthy of the respect of others. Often a person who lacks this sense of personal worth may try to compensate for it by achieving greater competence in one or more skills, but this attempt will not work, because it does not remedy the underlying source of the problem.
The excess of competence cannot compensate for a lack of self-esteem any more than large doses of vitamin B can compensate for a lack of vitamin C. The only cure is for one to respect and value oneself.
A person should have this basic sense of worthiness by virtue of the awareness that he possesses a Divine neshamah, or soul, and the daily prayer, "My God, the neshamah You have placed within me is pure," should affirm this sense of self-worth. If one has behaved in a manner that has soiled his pure neshamah, one can restore its purity through repentance. A sense of self-worth is therefore always attainable through proper behavior and by correcting any improper behavior via teshuvah or repentance. Of course, every person should work to achieve his personal maximum - but he should do so for its own sake, and not in order to compensate for a lack of self- worth.