make a believer (out) of (one)
To convince or persuade one to believe or have faith in someone or something. I was really skeptical of his supposed breakthrough, but the demonstration he gave us made a believer of me. Their absolute dominance in the first game of the tournament made believers out of the entire city—now everyone is throwing their support behind the home team!
true believer
One who passionately supports a cause or concept. My sister is a true believer in social equality, so she is out at the protest today.
Farlex Dictionary of Idioms. © 2024 Farlex, Inc, all rights reserved.