Caitanya Mahāprabhu says to Rūpa Gosvāmī that we are wandering in this way, brahmāṇḍa, whole universe. There are different types, or forms, of body, 8,400,000. And there are millions and trillions of planets, up and down. Oṁ bhūr . . . bhūr bhuvaḥ svaḥ. Bhūrloka, Bhuvarloka, Svarloka, Janaloka, Maharloka, Tapoloka. Then Tala, Atala, Vitala, Pātāla, Rasātala . . . there are so many planetary system. Caturdaśa-bhuvana. This universe is called fourteen different planetary system, and we are wandering in these different planetary system. If we are pious, then we are promoted to the higher planetary system, Svargaloka, Janaloka, Maharloka, Tapoloka, Brahmaloka, Satyaloka. There are so many . . . Siddhaloka. And if we are impious, then we are downtrodden. We go down more and more. Ūrdhvaṁ gacchanti sattva-sthāḥ (BG 14.18). If you are situated in sattva-guṇa, then you are promoted to the higher planetary system: adho gacchanti tāmasāḥ. Jaghanya-guṇa-vṛtti-sthā adho gacchanti tāmasāḥ. If you are infected with tamo-guṇa, then you go down, down, down, down. Madhye tiṣṭhanti rājasāḥ: and if we are infected by the modes of passion, then we keep ourself in the middle. But Kṛṣṇa says in the Bhagavad-gītā, ābrahma-bhuvanāl lokāḥ punar āvartino 'rjuna (BG 8.16). Even if you go to the highest planetary system—it is called Brahmaloka—where the duration of life is very, very long . . . that is described in the Bhagavad-gītā, sahasra-yuga-paryantam ahar yad brahmaṇo viduḥ (BG 8.17).
So the . . . sādhu. We are to take shelter of sādhu. Sādhu-guru, the same thing. Guru means sādhu. A sādhu . . . one . . . sādhu means the devotee of the Lord. If one is not sādhu, then he cannot become guru. And sādhu means . . . this is the description given. What is that? Mayy ananyena bhāvena bhaktiṁ kurvanti ye dṛḍhām. He's sādhu. Not that anyone with a saffron cloth and having a long beard. That is not sādhu. Sādhu means the devotee of the Lord. That is his first qualification. Kṛṣṇa says, api cet su-durācāro bhajate mām ananya-bhāk. The same thing. As it is . . . Kapiladeva says, mayy ananyena bhāvena. Kapiladeva is also Kṛṣṇa, incarnation of Kṛṣṇa. The same thing. The Bhagavad-gītā, Kṛṣṇa svayam says, bhajate mām ananya-bhāk. Ananya, "Not being deviated." Mām ekam, "Only unto Me." This is ananya-bhāva. Not that sometimes take from here something, take from here something, whatever is available. Those who are after material concession, they go different demigods: take something from Śiva, take something from Durgā, take something from Kālī, take this, that, that. So many, there are different demigods, especially Goddess Durgā, Lord Śiva and Gaṇeśa and Sūrya, they are . . . and Viṣṇu. The Viṣṇu worship is the best. Ārādhanānāṁ sarveṣāṁ viṣṇor ārādhanaṁ param (Padma Purāṇa). That is said by Lord Śiva to Goddess Pārvatī. Pārvatī asked Lord Śiva, "What is the best type of worship?" There are so many. It is amongst the demigods. So Lord Śiva advised, ārādhanānāṁ sarveṣāṁ viṣṇor ārādhanaṁ param. "My dear Pārvatī, amongst all kinds of different types of worship, Viṣṇu worship is the best." And then again he said, tasmāt parataraṁ devi: "And there is still better worship." What is that? Tasmāt parataraṁ devi tadīyānāṁ ārādhanānāṁ. Then . . . "Viṣṇu worship is the best. And more than that: to worship Vaiṣṇava." Tadīyānāṁ ārādhanānāṁ.