BG Chap 10 - Gaining direct contact with Kṛṣṇa
A person may have a bona fide spiritual master and may be attached to a spiritual organization, but if he is still not intelligent enough to make progress, then Kṛṣṇa from within gives him instructions so that he may ultimately come to Him without difficulty. The qualification is that a person always engage himself in Kṛṣṇa consciousness and with love and devotion render all kinds of services. He should perform some sort of work for Kṛṣṇa and that work should be with love. Kṛṣṇa appears within the heart of those who constantly desire to be with Him and worship Him with great love. By this appearance in their heart, they attain Kṛṣṇa’s direct association. To those who are constantly devoted to serving Him with love, Kṛṣṇa gives the understanding by which they can reach Him. The Lord alone causes buddhi yoga to appear within the functions of the hearts of devotees. This bhakti yoga cannot be obtained from any other source, and can be given only by Kṛṣṇa and received only by the devotee. This is how it is possible to realize Kṛṣṇa as being endowed with infinite forms, qualities and powers. Then one will be able to worship Him and attain Him.