Enlightenment is realizing the empty and impermanent nature of ourselves and the world. If you can live in emptiness without attaching to it, it is called "neither abiding in existence nor emptiness." Although everything continues to exist, there is no self that attaches to anything. Not abiding in existence and not abiding in emptiness is enlightenment. When this stage of practice is perfected, it is called Complete Enlightenment, or Buddhahood.

On the path to enlightenment, you begin by letting go of the past and future. You reside in the present, working on your method. This is the path. Eventually, even the method and the present must be dropped, for they are attachments as well.

Ch'an Master Lin-chi told his disciples to kill any Buddha or Bodhisattva that they met on the path. He also told them to kill their parents if they met them on the path. Of course he did not mean it literally. He meant you must kill your illusions while you practice. Drop everything. Kill everything in your mind of attachment. This is the correct attitude for practitioners involved in intense practice.