Asmin dehe, "In this body, there is the proprietor, the soul." Dehino 'smin yathā dehe. That, on account of the proprietor, he is changing body. Changing body means... So long the soul is there. Suppose a child is born. If the child is born dead, then this body will never grow. You can apply any chemicals or any science; the body will remain the same. But so long the soul is there within the body, the child from the babyhood will come to childhood, then childhood to boyhood, boyhood to youthhood. In this way the body will change. We have changed so many bodies, every one of us. I knew, I know that I had a childish body, I had a boyhood body, but those bodies are no more existing. But I am existing. Therefore the conclusion should be that I, you, as soul, we are eternal. The body is changing. This is our disease. Therefore this disease... This disease means birth, death, old age and disease. So as soon as you accept this body, material body, you become subjected to the four laws of material nature. These four laws of material nature are that as soon as you've accepted this body, then you must accept death. Anything which is born must meet death also. Birth, death. And in the via media there is old age and disease. This body... I have got, you have got, everyone. There is a death of getting this body, and there will be a death of leaving this body. And between these two deaths there are so many other miserable conditions. They are summarized: old age and disease. But the real science is that "I am the soul. I am the part and parcel of the Supreme Lord. So Supreme Lord, God, is eternal. I am also eternal." These things are described. Na hanyate hanyamāne śarīre (BG 2.20). As God, we are as good as God, at least in quality, not in quantity. We are... Just like a drop of sea water is as good as the sea water in quality—the whole sea water is also salty, and the drop of sea water is also salty—similarly, we have got all the chemical composition, or qualities, of God. Now, God is eternal; therefore we must be eternal. That is stated in the Bhagavad-gītā. Na hanyate hanyamāne śarīre (BG 2.20). After destruction of this body, the soul is never destroyed. This is our real, constitutional position. Then why we have accepted this changing process: birth, death, old age and disease? This is our material life.
So this is the education, that we should understand what is our material life and what is our spiritual life. Spiritual life means sac-cid-ānanda-vigraha (Bs. 5.1). Sat-cit-ānanda. Sat means eternal, cit means full of knowledge, and bliss means full of jubilation, ānanda, pleasure. This is our constitution. This is God's constitution. This our constitution. The difference between God and ourself is that God never accepts this material body, but sometimes we, under certain circumstances, we have to accept this material body. But never mind. We have accepted this material body. We can get out of it. And the process for getting out of it is Kṛṣṇa consciousness. This is the science. Kṛṣṇa consciousness movement means we are teaching people how to get out of this entanglement of birth, death, old age and disease and become as good as God. This is Kṛṣṇa consciousness movement. It is very scientific movement, authoritative movement. So not only it is authoritative, it is accepted by millions and thousands. At least in India there are many. And in the Western countries also, they are also accepting because it is scientific. They are not fools and rascals.