“What is a reprobate mind?”
The phrase “reprobate mind” comes from the old English translation of Romans 1:28, where Paul declares that when men and women reject the knowledge of God and refuse to honor and give thanks to him, God gives them up to a “reprobate mind”.
The Greek word underlying the translation is adokimos, which means literally “not approved”, and refers to something that does not meet objective standards of acceptability; for example, a counterfeit coin, a metal alloy which doesn’t hold up when subjected to stress, or soil that looks normal but in which nothing can grow.