Be not deceived (μη πλανασθε). Prohibition with μη and the present passive imperative of πλαναω, common verb to lead astray. This is the way of sin to deceive and to kill (Romans 7:7-14). The devil is a pastmaster at blinding men's eyes about sin (2. Corinthians 4:4; Romans 1:27; Ephesians 4:14; etc.).