What is that yoga? Man-manā bhava mad-bhakto mad-yājī māṁ namaskuru (BG 18.65). Mad-āśrayaḥ yogaṁ yuñj . . . yogaṁ yuñjan mad-āśrayaḥ. Mad-āśrayaḥ, this word is very significant. Mat means . . . "Either you take directly . . ." that is not very easy thing, " . . . shelter of Me, or one who has taken shelter of Me, you take shelter of him." Just like there is electric powerhouse, and there is a plug. That plug is connected with the electric powerhouse, and if you push your wire in the plug, you also get electricity. Similarly, as it is stated in the beginning of this chapter, evaṁ paramparā-prāptam imaṁ rājarṣayo viduḥ (BG 4.2). If you take shelter of the paramparā system . . . the same example—if you take the shelter of the plug which is connected with the powerhouse, you get immediately electricity. Similarly, if you take shelter of a person who is coming in the paramparā system . . .
There is a paramparā system. Kṛṣṇa, He instructed Lord Brahmā. Lord Brahmā instructed Nārada. Nārada instructed Vyāsadeva. Vyāsadeva instructed Madhvācārya. Madhvācārya instructed in so many ways. Then Mādhavendra Purī. The Mādhavendra Purī, Īśvara Purī. From Īśvara Purī, Lord Caitanya. In this way, there is a paramparā system. There are four Vaiṣṇava sampradāyas: the Rudra-sampradāya, Brahma-sampradāya, Kumāra-sampradāya, and Lakṣmī-sampradāya, Śrī-sampradāya. So sampradāya-vihīnā ye mantrās te niṣphalā matāḥ (Padma Purāṇa). If you do not receive instruction of Kṛṣṇa from the sampradāya, then niṣphalā matāḥ, then whatever you have learned, it is useless. It is useless. That is the defect.