Ephesians 4:17
So I tell you this, and insist on it in the Lord, that you must no longer live as the Gentiles do, in the futility of their thinking — Paul's stern command (oun legō, 'I say then,' 'I insist') forbids the Gentile believers to peripateo ('walk,' conduct themselves) as the ethnē ('nations,' pagan Gentiles), en mataiotes ('in futility,' emptiness) of their dianoia ('thinking,' their distorted understanding).