The phrase "am of" typically means "I belong to" or "I am a part of." Some synonyms for this phrase could include "am a member of," "am associated with," "belong to," "are part of," or "am affiliated with." These alternatives can be useful in avoiding repetition and adding variety to your writing. For example, instead of saying "I am of the opinion that...", you could say "I am of the mindset that..." or "I hold the belief that..." Using synonyms can also help to clarify your meaning and make your writing more engaging for your audience.