When it comes to expressing the significance of something, there are several synonyms for the phrase "be important." Some alternatives include "be crucial," "be essential," "be pivotal," "be vital," "be critical," and "be paramount." These words are perfect for emphasizing the gravity of a situation or the impact of a decision. Additionally, other synonyms include "be significant," "be meaningful," "be imperative," "be indispensable," and "be necessary." These synonyms can be used interchangeably with "be important," but they offer a more nuanced way of expressing the importance of something. Regardless of which synonym is used, the message remains clear: the subject in question is not to be taken lightly.