One cannot take to Kṛṣṇa consciousness unless he is completely washed of all sinful activity. So we forbid four things, because they are pillars of sinful activities: illicit sex life, intoxication, meat-eating and gambling. Unless one gives up these four sinful activities it is not possible to approach Kṛṣṇa. Kṛṣṇa clearly says in the Bhagavad-gītā, yeṣām anta-gataṁ pāpam. Pāpam means sin. One who has finished the sinful activity. And these are four pillars of sinful activity.
So we have to voluntarily give up these habits. That is called austerity, penance. The human life is meant for austerity and penance, not for increasing the items of our sense gratification. That is animal life. Human life is meant for restraint. Laws are for the human being. When you go to the street—"Keep to the left"—this law is meant for human being, not for the dog. The dogs can go from left to right; he has no punishment. But if you go from left to right, violating the rules or violating the color, symbol, signal, then you will be immediately arrested, because you are human being.
So all the laws or injunctions are for human being. So human being, human life, is very responsible life. As you cannot violate the state law, similarly, you cannot violate the laws given by God. That is called dharma. Dharmaṁ tu sākṣād bhagavat-praṇītam (SB 6.3.19). Religion means the laws of God. If you violate, then you are punished. That's all.