true believer

noun

1. a person who has been thoroughly convinced of something.

2. a fanatic, especially a religious or political one.

Example Sentences

Milei is a libertarian true believer whose reckless budget-slashing has driven Argentina into a deep economic crisis.

From Salon

Greene, at least, seems to be a true believer in the cause, and she seems to genuinely want the Epstein files released.

From Slate

I went to Texas dubious, but 9,000 calories later, I’m afraid I’ve become a true believer.

From Slate

So while Fuentes may survive longer as a true believer, he’ll never gain as much money and influence as the grifters.

From Salon

When Harper asks Pam if anyone ever left the group after just one turn of the Wheel, Pam — a true believer — can’t fathom backing out of the group.

From Los Angeles Times