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).