Preaching to the choir is an idiom about the foolish attempt of arguing or attempting to convince those who already agree with you.
It is used to allude to acts that are futile because they have already been achieved.
The first version of the expression appeared in British English during the 1850’s, as “preaching to the converted”.
The current form of the idiom was first used in America during the 1970’s and it has been around ever since.
“Preaching to the choir” is a widely used idiom in the US, and has appeared as the title of multiple songs from artists like Rodney Crowell, or Nona.
The expression was first defined on Urban Dictionary in 2004.
- Merriam-Webster – Preach to the choir