Yasya prabhā peabhavato (Bs. 5.40). In the Brahma-saṁhitā we get this information: yasya prabhā prabhavato jagad-aṇḍa-koṭi. Jagad-aṇḍa. Jagad-aṇḍa means universes. Koṭi means innumerable, hundreds of thousands multiplied by another hundred, hundred, hundred. Lord Caitanya Mahāprabhu has said that this universe is a grain of mustard seed in the bag of a mustard seed. Just imagine. Can anyone count what is the number of mustards seeds in a bag, in a one-ton or two-ton bag? Innumerable. It is beyond our experience. But there are so many universes, just like packed up in a bag. This is called material world.
So what to speak of the spiritual world? The spiritual world is at least three times greater than this material world. That information we get from Bhagavad-gītā. Ekāṁśena sthito (BG 10.42)
Ekam means one part. Even you take . . . one part, maybe, one of hundred. But even not going so far, one part means divide the whole thing into four parts; that will be one fourth. This material world is only one fourth of the whole creation, and the three-fourth part is spiritual world.
In the spiritual world there is similarly innumerable planets, innumerable living entities. Just like, as I have already explained, that this material world is the just like prison house of the criminals. So our criminal department in the state, say, jail or prison house, that is not the countrywise, as big as the country. That is a fractional part only. Maybe a few hundred people or few thousand people living there, but the state is very big.
Similarly, the Lord's state is so big, though the criminal living entities are living in a corner only. This material world is in a corner. So what information we can get about God? "God is great," we simply theoretically say, but we do not know how great it is . . . He is, and how His greatness is working. That we do not know. But Kṛṣṇa conscious persons, because they are getting knowledge from Kṛṣṇa directly, they have got all this knowledge. Therefore their knowledge is perfect.
"If one were to begin to study ISKCON techniques, what would he have to give up?"
Give up . . . give up means . . . first give up is that "I am this material body." The nonsense idea that, "I am this body," that is the root of all misunderstanding. So he has to give up this bodily consciousness. That is naturally. There will be beginning of teachings of Kṛṣṇa consciousness. The Bhagavad-gītā teaches Arjuna. Arjuna was overwhelmed of family affection, that "How can I fight with my members of the family? They are my brothers . . ."