We know that there is something which distinguishes a dead body from a living body. That we can understand. Suppose your father dies. You will lament, "Oh, my father is no more! He has gone away." But where has he gone? Your father is lying on the bed. Why do you say that your father has gone away? "No, he is dead and gone." This shows you understand that the body lying on the bed is not your real father.
So, actually, you have no eyes to see your real father. During the lifetime of your father you did not know who he was. Therefore, when the actual father goes away, you cry, "My father is gone!" The actual father is the spiritual soul within the body. And when the soul goes away from the body, that is known as death.
At the present moment everyone is acting according to the bodily conception of life. But we are not the body. So we are acting for something that we are not.
Therefore, we are in Maya, or illusion. Our whole existence is a phantasmagoria. And because we are working for something that we are not, we are confused and unhappy. We work day and night for the body, and still we are not happy. We are trying to satisfy the senses (body means "senses"), repeating the same activities again and again, but we are finding no happiness. We cannot find happiness by trying to satisfy the material body, because we are not the material body. We are spiritual souls.
So if we are serious, if we actually want to be happy, we must take to the cultivation of spiritual understanding, an understanding of GOD consciousness.