Gava in service of G-d:
Although in general ego is a negative trait that must be worked on and is the source of all evil and lusts, nevertheless in the start of one’s Avodas Hashem, one must use his ego to battle the evil and serve G-d. One who serves Hashem and arouses a deep passion for Him, is certainly using his ego, as he desires to attach to G-d and he enjoys the feeling of passion, and he is saddened when he cannot arouse it. It is not the respect of G-d that bothers him, but the fact that he does not have this enjoyable feeling of closeness. Nevertheless, although this Avoda involves ego, it must be utilized when one is in his beginning stages of service, as if one begins serving Hashem with absolute nullification he will not have the strength to battle the evil lusts that still challenge him.
 Torah Or Megilas Esther p. 121c