(Srila Prabhupada and Kartamashi, Montreal 1975)
Prabhupāda: Vaiṣṇavas do not require to practice any yogic power to become materially powerful. He doesn't require. Simply his surrender to Kṛṣṇa makes him all-powerful. This is the position of Vaiṣṇava. Vaiṣṇavas, they do not care for all these yogic power. They depend on Kṛṣṇa. And who can be... Kṛṣṇa is the yogeśvara, all, master. Yatra kṛṣṇo... Yatra yogeśvaraḥ kṛṣṇaḥ (BG 18.78). So if one takes shelter of the Yogeśvara, the master of all mystic power, why he should bother about this yogic power? A poor man may try to earn money by hard labor, but one who is a very, very rich man's son, why should he labor? The father's money is sufficient. Similarly, a devotee, a sincere devotee, he is under the protection of Kṛṣṇa. And under the protection of Kṛṣṇa means under the protection of all six kinds of opulences: riches, then strength, then reputation, wisdom, renunciation, beauty—the six kinds of opulence.
Kṛṣṇa, under... Yaṁ labdhvā cāparaṁ lābhaṁ manyate nādhikaṁ tataḥ (BG 6.22). This is stated here. Because if you get somehow or other Kṛṣṇa's favor, then there is no question of any more profit. Sufficient profit. You have got everything. Simply be sincere to the service of Kṛṣṇa. Then you have got everything. There is no need of trying for this or that. Yasmin sthite guruṇāpi duḥkhena na vicālyate (BG 6.23). If one is situated under the shelter of Kṛṣṇa's lotus feet, then guruṇāpi duḥkhena na vicālyate. If there is dangerous type of inconvenience, then he's not disturbed. He knows... Just like Ambarīṣa Mahārāja, Prahlāda Mahārāja. There are many instances. His father, Hiraṇyakaśipu, was giving him trouble, chastising. He was patient, not disturbed. So be sure that if you are..., if you have actually taken shelter of the lotus feet of Kṛṣṇa, there is no question of danger. Kaunteya pratijānīhi na me bhaktaḥ praṇaśyati (BG 9.31). And Kṛṣṇa confirms it: "Kaunteya, My dear Arjuna, you declare to the world that My devotee will be never vanquished by any enemy." That is Kṛṣṇa's assurance.
(Srila Prabhupada Lecture, Vrindavan, August 4, 1974)