Other forms: believers
A believer is somebody who accepts a faith or an idea. A true believer, believers and non-believers, a firm believer in.
In religion it means somebody of that faith. The construction a believer in is very common outside religion: a firm believer in early nights, a great believer in doing it properly — where it means somebody strongly convinced of a practice's value. True believer is often faintly critical and means somebody whose conviction has stopped responding to evidence. Note believe, belief, and unbeliever.
1nounbelieverSomebody who accepts a faith or an idea.
“My grandmother was a devout believer and went to church every day.”
2nounstronglySomebody strongly convinced of a practice's value.
“She is a firm believer in reading the instructions.”
believer is somebody convinced.
The word is believe plus -er. Believe comes from Old English geliefan, built on the root that gives love and lief — believing began as holding dear rather than holding true.
Middle English
bilevar
English, today
believer
From believe + -er. From Middle English bilevar, bileever, belever, equivalent to believe + -er.
Etymology from Wiktionary, CC BY-SA