believer

UK: bɪˈliːvə | US: bɪˈliːvər

Definition
  1. n. a person who accepts something as true or real, especially without proof

  2. n. a person with religious faith; a follower of a particular religion or doctrine

Structure
believe <to accept as true>er <agent noun suffix>
Etymology

The word "believer" originates from the verb "believe," which comes from Old English belēfan ("to have faith"), itself derived from Proto-Germanic ga-laubjan ("to hold dear, trust"). The suffix "-er" is an agentive suffix in English, indicating a person who performs the action of the verb. Thus, "believer" literally means "one who believes," reflecting its core meaning of a person who holds faith or accepts something as true.

Examples
  1. She is a firm believer in the power of positive thinking.

  2. As a devout believer, he attends church every Sunday.

  3. The scientist remained a believer in the theory despite criticism.

  4. Many believers gathered to celebrate the religious festival.

  5. He’s not just a skeptic; he’s an active believer in the cause.