Drink the Kool Aid
Meaning
Accept a belief or plan unquestioningly, often to the point of self harm.
Usage
Used as a warning against cultish or blind loyalty.
Origin & History
Origin notes can vary by region and source; this page gives the commonly reported explanation and usage context.
Refers to the Jonestown tragedy where followers drank flavoring powder laced with poison.
Phrase entered English in the late 1970s after the tragedy.