We practice the genuine dharma because it is a method for clearing away the temporary s tains that obscure our vision of the true nature of mind. The abiding nature of our mind is clear light. It is the buddha nature, the undifferentiability of clarity and emptiness. In its essence, it is primordially pure and primordially free from any stain at all. It has been free and pure from the very beginning. Yet, although this is the basic nature of mind, there are temporary, adventitious stains, which are not of the nature of mind but which, nevertheless, prevent us from realizing what it is.
The fact that the true nature of mind could be this clear light, the buddha nature that is completely free of any imperfection at all, and yet be obscured by temporary stains, is called the first of the "four inconceivable points" in a text called the Gyü Lama. This text presents the highest view in the continuum of the Mahayana teachings. Why is this point inconceivable? It seems to be quite a contradiction to state that the basic nature of mind is pure and, at the same time, there are stains that prevent us from seeing it. If the true nature of our mind is pure, why then don’t we realize this?
The situation is like gold that is pure and yet is obscured by some coarser mineral; it is like water that is pure in essence, and yet is muddied by dirt; it is like the sun that is shining and yet is blocked from our view by clouds. The purpose of practicing dharma is to clear away these temporary stains so that the essence of mind shines forth. At that time, mind will be like pure gold that is refined of all impure materials. It will be like pure water, uncontaminated by any trace of dirt. It will be like the sun shining in a cloudless sky. We can understand how this apparently contradictory point is not contradictory when we consider such examples. On the surface, there might appear to be a contradiction while, fundamentally, there is not.
The qualities of the basic nature of this clear light, or buddha nature, are that it is naturally open, spacious and relaxed. When a person realizes this directly, they are freed from the bondage of their conceptuality; they are no longer bound by conceptual mind. Further, this realization benefits not only those who have experienced it directly, but it also benefits us while we are still in the process of listening to and reflecting upon these teachings. As we develop our understanding, we progressively gain certainty that the nature of this mind will help to release us from the bondage of our thoughts, and from the bondage of our own anger and desire.