One who seeks that objective is the real student of Bhagavad-gītā, but one who doubts the authority of Kṛṣṇa falls back. One is therefore advised to study Bhagavad-gītā, or any other scripture, under a bona fide spiritual master, with service and surrender. A bona fide spiritual master is in the disciplic succession from time eternal, and he does not deviate at all from the instructions of the Supreme Lord as they were imparted millions of years ago to the sun-god, from whom the instructions of Bhagavad-gītā have come down to the earthly kingdom.
(Bhagavad-Gita--4:42----purport).

But actually the original father of this movement is Lord Kṛṣṇa Himself, since it was started a very long time ago but is coming down to human society by disciplic succession.
(Bhagavad-Gita-preface).

One should act according to the order of Kṛṣṇa. This is a very important point. That order of Kṛṣṇa comes through disciplic succession from the bona fide spiritual master. Therefore the spiritual master's order should be taken as the prime duty of life. If one gets a bona fide spiritual master and acts according to his direction, then one's perfection of life in Kṛṣṇa consciousness is guaranteed.
(Bhagavad-Gita---18:57---purport).

The ripened fruit is not dropped all of a sudden from the highest planet of Kṛṣṇaloka. Rather, it has come down carefully through the chain of disciplic successionwithout change or disturbance. Foolish people who are not in the transcendental disciplic succession commit great blunders by trying to understand the highest transcendental rasa known as the rāsa dance without following in the footsteps of Śukadeva Gosvāmī, who presents this fruit very carefully by stages of transcendental realization.
(Srimad Bhagavatam---1:1:3---purport).

The Lord's order descends in disciplic succession through the bona fide spiritual master, and thus execution of the order of the bona fide spiritual master is factual control of the senses. Such execution of penance in full faith and sincerity made Brahmājī so powerful that he became the creator of the universe. And because he was able to attain such power, he is called the best amongst all the tapasvīs.
(Srimad Bhagavatam----2:9:8---purport).