One must seek the association of persons who are Kṛṣṇa conscious and who engage in devotional service. Without such association one cannot advance. Simply by theoretical knowledge or study one cannot make any appreciable advancement.
One must give up the association of materialistic persons and seek the association of devotees because without such association one cannot understand the activities of the Lord. Generally, people are convinced of the impersonal feature of the Absolute Truth. Because they do not associate with devotees, they cannot understand that the Absolute Truth can be a person and have personal activities. This is a very difficult subject matter, and unless one has personal understanding of the Absolute Truth, there is no meaning to devotion. Service or devotion cannot be offered to anything impersonal. Service must be offered to a person. Non-devotees cannot appreciate Kṛṣṇa consciousness by reading the Srimad-Bhagavatam or any other Vedic literature wherein the activities of the Lord are described; they think that these activities are fictional, because spiritual life is not explained to them in the proper mood. To understand the personal activities of the Lord, one has to seek the association of devotees, and by such association, when one contemplates and tries to understand the transcendental activities of the Lord, the path to liberation is open, and he is freed. One who has firm faith in the Supreme Personality of Godhead becomes fixed, and his attraction for association with the Lord and the devotees increases. Association with devotees means association with the Lord. The devotee who makes this association develops the consciousness for rendering service to the Lord, and then, being situated in the transcendental position of devotional service, he gradually becomes perfect.
In all scriptures people are encouraged to act in a pious way so that they can enjoy sense gratification not only in this life but also in the next. For example, one is promised promotion to the heavenly kingdom of higher planets by pious fruitive activities. But a devotee in the association of devotees prefers to contemplate the activities of the Lord-how He has created this universe, how He is maintaining it, how the creation dissolves, and how in the spiritual kingdom the Lord’s pastimes are enacted. There are full literatures describing these activities, especially Bhagavad-gita, Brahma-samhita and Srimad-Bhagavatam. The sincere devotee who associates with devotees gets the opportunity to hear and contemplate these subjects, and the result is that he feels distaste for so called happiness in this or that world, in heaven or on other planets. The devotees are simply interested in being transferred to the personal association of the Lord; they are no longer attracted to temporary so called happiness.
In other words, when there is no devotee of the Lord present, there is great suffering in society, and association with other people becomes painful. In Srimad-Bhagavatam (3.30.7) it is stated that if one who is bereft of the association of a pure devotee tries to become happy though society, friendship and love devoid of Kṛṣṇa consciousness, he is to be considered in the most distressed condition. In the Fifth Canto of Brhad-bhagavatamrta (5.44) it is stated that the association of a pure devotee is more desirable than life itself and that in separation from him one cannot even pass a second happily.
Source: A.C. Bhaktivedanta Swami Prabhupada (2007 edition), “Teachings of Lord Kapila, The Son of Devahuti”, Page 157 & 158,
A.C. Bhaktivedanta Swami Prabhupada (2012 edition), “Teachings of Lord Caitanya, The Golden Avatara”, Page 381