Man's mind is made up of illusionary pictures. Consequently, when he throws away these pictures Truth will enter into his mind, and he will know Truth to the extent of what he has discarded. This is enlightenment.
People do not know what Truth is and what false is. Truth knows both Truth and falseness. However, the false know neither the false nor Truth. People do not know what Truth is, nor do they know what they are being deceived by. When they have a bigger mind and become Truth, they will know the wisdom of the world and will live without death.
It is the same principle as washing dirty clothes - the more you clean the dirt away, the more it goes back to its original state. A piece of paper, which has been scribbled on, gets cleaner the more the scribbling is erased. Enlightenment is the same as knowing the true state of the paper once it is clean.