Beginning from the germs up to the heavenly kingdom . . . the king of heaven is called Indra, and the smallest, minutest germ, it is also called indra-gopa in Sanskrit language. So in the Brahma-saṁhitā (Bs 5.54) it is said that, "Beginning from this indra up to that Indra . . ." That means "Beginning from the germ which is known as indra-gopa up to the point of the king who is also known as Indra, all of them are bound up by the reaction of his own karma, or his own work."
Every work which you are doing, good or bad, we have to suffer or enjoy the reaction of our work. And so long we have to suffer or enjoy the reaction of our work, as long as we shall go on like this, so long we have to accept this material body. This material body is just given to us by the arrangement of nature's law for the exact status of suffering or enjoyment.
Just like you have seen different animals, they have got different process of eating. Say for tiger. Tiger, they have bodies made for eating raw flesh and raw blood. So all the body is so made that they have got particular nails and jaws and teeth so that they can do that.
Similarly, you can see the hog. They have to eat the stool. Oh, they have got a particular shape of mouth so that they can easily do that. Now, we are human being. We are meant for taking vegetables and fruits. Now, our teeth is just like knife which can cut the vegetables and the fruits.
So all these bodies, I mean to say . . . I am giving particular stress to the body. A king's body, a poor man's body. A poor man, he has to work very hard. His body is very sturdy. He can work very nicely. But a son of very aristocratic family or king, oh, his body is very delicate. He cannot work. He can apply his brain in something else.
So, so long we are . . . these bodies are made according to the different status of our work we have done in our past life. And next body is being prepared according to the work which we are doing now. But here Kṛṣṇa says that as soon as one can understand the transcendental nature of Kṛṣṇa's activities, he becomes free from the reaction of activities.
Now, here is the question, that because we are now preparing ourself to have our spiritual body or spiritual life developed, and being freed from this material existence, therefore our duty should be such so that we may not be entangled again into this material body. That can be made possible if we are Kṛṣṇa conscious. If we study Kṛṣṇa, what is Kṛṣṇa, what are His transcendental activities, how His energies are acting in this material world or spiritual world, all this . . . it is a great science. Kṛṣṇa is a great science.