Imagine what it would be like if you were a subtle creature, not made of material stuff like cells and organs, but rather if you were made of light, like the body you experience in dreams. You could fly, change shape, do anything at will, and not die. Now imagine that although you were this subtle creature, you also had a material body, and that this material body's senses shout so loudly that you've lost awareness of your subtle body. This is the situation we are all in. We are beings of light and we mis-identify with the physical body. This is the message of the great yoga sages. Yoga is a means to discover this truth, to remove the illusion that we are only the dense physical body rather than a being of light.