Caitanya Caritamrta Antya 6.278
TRANSLATION When one eats food offered by a materialistic man, one’s mind becomes contaminated, and when the mind is contaminated, one is unable to think of Krsna properly.
PURPORT Srila Bhaktisiddhanta Sarasvati Thakura suggests that people who are materialistically inclined and sahajiyas, or so-called Vaisnavas who take everything very casually, are both visayis, or materialists. Eating food offered by them causes contamination, and as a result of such contamination, even a serious devotee becomes like a materialistic man. There are six kinds of association “giving charity, accepting charity, accepting food, offering food, talking confidentially and inquiring confidentially”. One should very carefully avoid associating with both the sahajiyas, who are sometimes known as ‘Vaisnavas’, and the non-Vaisnavas, or avaisnavas. Their association changes the transcendental devotional service of Lord Krsna into sense gratification, and when sense gratification enters the mind of a devotee, he is contaminated. The materialistic person who aspires after sense gratification cannot properly think of Krsna.