"The surrendering process is completed by the influence of association. The Lord has suggested, therefore, that by the influence of the speeches of saintly persons who have actually realized the Supreme, men are engaged in His transcendental loving service. The conditioned soul gets a taste for hearing about the Lord, and by such hearing only he is gradually elevated to the platform of respect, devotion and attachment for the Lord."
"The Lord can be realized through the aural reception of the transcendental message, and that is the only way to experience the transcendental subject. As fire is kindled from wood by another fire, the divine consciousness of man can similarly be kindled by another divine grace. His Divine Grace the spiritual master can kindle the spiritual fire from the woodlike living entity by imparting proper spiritual messages injected through the receptive ear. Therefore one is required to approach the proper spiritual master with receptive ears only, and thus divine existence is gradually realized."
"My Guru Maharaja used to say, "Don't try to see a saintly person by your eyes. You see a saintly person by the ear." Because if you hear from the saintly person and if he is speaking from the experience which he has heard from the, another saintly person--this is called guru-parampara--then the knowledge is perfect."
Srila Prabhupada Lecture on Srimad-Bhagavatam, 06-08-76, Los Angeles
"The process for Krsna consciousness is that we control the mind through hearing and chanting. We hear the maha mantra, Hare Krsna Hare Krsna Krsna Krsna Hare Hare Hare Rama Hare Rama Rama Rama Hare Hare and we hear the lectures from the spiritual master and read his books. Also we speak by preaching and by chanting. This is the easy method for controlling the mind, by hearing and chanting."
Srila Prabhupada Letter to Sharon Suzuki, 09-04-75
"One must be very meek and submissive and try to live peacefully by lending the ear to the speeches of the transcendentally self-realized soul who speaks on the message of Bhagavata-dharma or the religion of glorifying the Supreme Lord and His devotees. To glorify a great man is a natural instinct for living beings, but they have not learned to glorify the Lord. Perfection of life is attained simply by glorifying the Lord in association with a self-realized devotee of the Lord. The self-realized devotee is he who surrenders unto the Lord fully and who does not have attachment for material prosperity. Material prosperity and sense enjoyment and their advancement are all activities of ignorance in human society. Peace and friendship are impossible for a society detached from the association of God and His devotees. It is imperative, therefore, that one sincerely seek the association of pure devotees and hear them patiently and submissively from any position of life."
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.