It is stated in the Bhagavad-gita, yesam anta-gatam papam: one who is completely free from all sinful activities, papam. Anyone who is engaged in sinful activities, he cannot understand Krsna, or God. That is not possible. And these are the four principles of sinful activities: illicit sex-life, intoxication, meat-eating and gambling. These are the four pillars of sinful activities. Why at the present moment people have become so godless? Even big, big swamis and yogis, all godless. Why? Because they are engaged in sinful activities. Krsna, God, cannot be understood by sinful men. That is not possible.
Lecture on Bhagavad-gita 9.2, Calcutta, 8 March, 1972