What is another word for be in the service of?
Pronunciation: [biː ɪnðə sˈɜːvɪs ɒv] (IPA) 
The phrase "be in the service of" can be used to indicate someone working diligently, dedicating their time and expertise to a particular cause. Synonyms for this phrase may include "serve," "help," "support," "assist," "aid," or "pledge oneself to." These words emphasize the idea of willingly giving oneself over to the service of another or a greater good. Other options include "be at one's disposal," "lend a hand," "be of use," or "be devoted to." Each of these phrases conveys the same sentiment, that of being fully committed to the service of another or a noble cause, and putting one's own interests aside for the betterment of others.
