John Calvin Commentary 1 Corinthians 15:33

"Be not deceived: Evil companionships corrupt good morals." — 1 Corinthians 15:33 (ASV)

Be not deceived. Evil communications corrupt good manners. As nothing is easier than to glide into profane speculation, under the pretext of inquiring, he addresses this danger by warning them that evil communications have more effect than we might suppose in polluting our minds and corrupting our morals.

To show this, he uses a quotation from the poet Menander, as we are free to borrow from every source everything that has proceeded from God. And as all truth is from God, there is no doubt that the Lord has put into the mouth of the wicked themselves whatever contains true and salutary doctrine. I prefer, however, that for addressing this subject, one should consult Basil’s Oration to the Young. Paul, then, being aware that this proverb was in common use among the Greeks, chose to use it instead, so that it might enter their minds more easily, rather than express the same thing in his own words. For they would more easily accept what they were accustomed to — as we have experience with proverbs with which we are familiar.

Now, this is a sentiment that is particularly worthy of attention, for Satan, when he cannot directly assault us, deceives us with the pretext that there is nothing wrong with our engaging in any kind of disputation for the purpose of investigating truth. Therefore, in opposition to this, Paul warns us that we must guard against evil communications, just as we would against the deadliest poison, because, insinuating themselves secretly into our minds, they immediately corrupt our entire life. Let us, then, take notice that nothing is more pestilential than corrupt doctrine and profane disputations, which lead us away, even in the slightest degree, from a right and simple faith; for it is not without good reason that Paul exhorts us not to be deceived.