Self esteem is extremely important in Judaism. For example, Rabbi Twerski, a modern writer of many books on serving G-d, stresses self esteem (see Let Us Make Man).

I was speaking to a man the other day and I began a sentence, "How would you react if someone did the following to you..." Suddenly I knew that this man, who has little self esteem, would respond that it wouldn't bother him in the least. I realized two things about self esteem.

There is a profound yet simple proof why a person is required in Judaism to increase their self esteem, and that is when they are asked "Would it bother you if..." they can answer an honest "Yes". This means they will be capable of empathizing with another person and doing something for another person with true feeling and committment.

The other thing is I finally found an answer to a question I always had. How can a person who has little self esteem begin to work on themselves in any area, self esteem included? The answer is simple. Many people who have low self esteem still are able to respect others. If they can understand that working on self esteem will better allow them sit in other people's shoes and understand others better, at least they have a starting point for beginning to work on self esteem.