The word "nonbelieving" refers to someone who does not believe in something, usually referring to religious or spiritual beliefs. Antonyms for this word include believers, faithful, devotees, adherents, followers, and supporters. These words refer to individuals who hold strong beliefs in a particular religion, ideology or philosophy. Someone who is a believer, for example, has faith and trust in a higher power or spiritual force. These antonyms highlight the opposite side of the spectrum, drawing attention to those who are committed to their belief systems, rather than those who lack belief or are skeptical. It is important to remember that beliefs differ among individuals, and these antonyms provide alternate perspectives on the topic.