In the Eleventh Canto, Second Chapter, of Śrīmad-Bhāgavatam, Vasudeva, the father of Kṛṣṇa, asks Nārada Muni about the welfare of all living entities, and in reply Nārada Muni quotes a passage from Mahārāja Nimi's discussion with the nine sages. "O holy sages," King Nimi said, "I am just trying to find the path of well-being for all living entities. A moment of association with holy men is the most valuable thing in life, for that moment opens the path of advancement in spiritual life." (SB 11.2.30) This statement is confirmed elsewhere in Śrīmad-Bhāgavatam (3.25.25). By associating with holy persons and discussing transcendental subject matters with them, one becomes convinced of the value of spiritual life. Very soon, hearing of Kṛṣṇa becomes pleasing to the ear and begins to satisfy one's heart. After receiving such spiritual messages from holy persons, or pure devotees, if one tries to apply them in his own life, one naturally and successively develops faith, attachment and devotion while progressing on the path of Kṛṣṇa consciousness.
The Lord then informed Sanātana Gosvāmī about the behavior of a devotee. The sum and substance of such behavior is that one should always stay aloof from unholy association. And what is unholy association? It is association with one who is too much attached to women or one who is not a devotee of Lord Kṛṣṇa. These are unholy persons. One is thus advised to associate with holy devotees of the Lord and carefully avoid the association of unholy nondevotees. Pure devotees of Kṛṣṇa are very careful to keep aloof from the two kinds of nondevotees. The result of unholy association is described in Śrīmad-Bhāgavatam (SB 3.31.33)-(SB 3.31.35). There it is said that one should give up all association with a person who is a plaything for women, for by associating with such an unholy person one becomes bereft of all good qualities, such as truthfulness, cleanliness, mercy, gravity, intelligence, shyness, beauty, fame, forgiveness, control of the mind, control of the senses, and all the opulences that are automatically obtained by a devotee. A man is never so degraded as when he associates with persons who are too much attached to women.