Apeithēs describes someone who is disobedient, unpersuadable, or refusing to comply with authority. Composed of the privative a- (not) and peithō (to persuade/obey), it characterizes those who will not be convinced or will not submit. Used in descriptions of pre-conversion conduct, the condition of the lost, and rebellious children.
The New Testament consistently uses apeithēs to describe the unregenerate condition — disobedient to God and governed by sinful desires (Titus 3:3; 2 Timothy 3:2). Paul's reminder that believers "once were" disobedient is a call to humility and gratitude: the grace that rescued us from our own stubborn refusal of God is the same grace we must extend to others.