I am very much pleased to receive your daily reports, and you are one of the best students who follows the regulative principles rigidly for enhancing the devotional service. Rupa Goswami has recommended that for enhancing this spirit of devotional service one should be very enthusiastic, one should be patient, one should be firmly convinced, one should follow the regulative principles rigidly, one's occupation should be very honest and straightforward, and one should keep company with devotees. Anyone who follows these six principles of devotional life is sure to achieve success.
Letter to Isana das, 23 May, 1969