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 seawater is as good as the seawater in quality—the whole seawater is also salty, and the drop of seawater 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).
(Kṛṣṇa who is known as Govinda is the Supreme Godhead. He has an eternal blissful spiritual body. He is the origin of all. He has no other origin and He is the prime cause of all causes.)
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.