Be not deceived: evil communications corrupt good manners.
Be not deceived - as though denial of the resurrection were a mere harmless speculation (1 Corinthians 6:9): nay, association with such unbelievers will corrupt good morals.
Evil communications corrupt good manners - a current saying, from the Thais of Menander, the comic poet, who took it, from Euripides (Socrates, 'Historia Eccleslastica,' 3: 16). "Evil communications" refer to conversatons with those who deny the resurrection. Their notion was that the resurrection is merely spiritual, that sin has its seat solely in the body, and will be left behind when the soul leaves it, if, indeed, the soul survive at all.
Good - not only good-natured, but pliant. Intimacy with the profligate around was apt to corrupt the principles of the Corinthians.