In order to guide the conditioned student to some purpose for which Kṛṣṇa descends to this planet once in a day of Brahmā, or every 8,600,000,000 years.
The Bhakti-sastri course is the official name for the study of the following four scriptures – Bhagavad-gita , The Nectar of Instruction, The Nectar of Devotion and Sri Isopanisad.