Antonyms for the phrase "be a consequence" can include phrases, such as "have no effect," "not matter," or "be unrelated." In essence, these phrases imply that there is no direct link between cause and effect. For example, if someone were to say that a person's actions would result in negative consequences, the antithesis might be to say that their actions would have no effect whatsoever. Alternatively, a person might say that a particular activity is entirely unrelated to a particular outcome, implying that there is no causal relationship between them. Ultimately, the use of antonyms for the phrase "be a consequence" can help individuals to better understand the nuances of language and how words and phrases can be used in different contexts.