Caitanya Mahāprabhu says, tṛṇād api sunīcena taror api sahiṣṇunā (CC Adi 17.31)—humbler that the blade of grass, and tolerant than the tree.
So these are the qualification, spiritual qualification. So if one becomes falsely proud, then where is his spiritual qualification? Everything is lost, everything gone—immediately. So in spite of his all good qualifications, if he is simply proud, then everything becomes zero.
Of course, not in this country . . . in our country milk is considered to be very nice, nutritious food; but if there is a drop of wine mixed with milk, it is no more pure; it is finished. If it is touched by the lip of the serpent, it is finished—no more.
Similarly, one may have all these qualifications if he becomes brahmin or kṣatriya, or very high class, very aristocratic, all this. That is all right. But if it is simply false prestige, if it is meant simply for showing one's false prestige, then those qualification have no value. And when there is no value, he cannot purify himself, what to speak of purifying his whole family.
But this man who is born in the family of śvapacaṁ, dog-eaters, because he has taken to Kṛṣṇa consciousness, because he has become humble and meek, because he has engaged his body, mind and words for the service of Kṛṣṇa, he can purify himself, and he can deliver his whole family.