There are several antonyms for the phrase "sware bible," which means to take an oath on the Bible. One antonym could be "disbelief," where one does not believe in the power of the Bible or the act of swearing on it. Another antonym could be "athiest," where one does not believe in any deity or religion, let alone swear on a religious text. "Skepticism" could also be an antonym, where one questions the validity of the Bible or the act of swearing on it. In short, there are several beliefs and attitudes that oppose the idea of swearing on the Bible, which could serve as antonyms for the phrase "sware Bible.