Not all self-esteem is created equal. Self-esteem is selfish when it is based in pride. This kind of self-esteem is actually detrimental to ourselves or others.
Self-esteem is only beneficial to the extent that it is based in meekness. We must believe that we are nothing without God, but with Him we can do everything. In that way we have great worth. Our meek self-esteem strengthens as we live closer to Him. We feel our self-worth through the constant companionship of the Holy Ghost.