From "Glimpse of the Day" -
Whatever our lives are like, our buddha nature is always there. And it is always perfect. We say that not even the buddhas can improve it in their infinite wisdom, nor can sentient beings spoil it in their seemingly infinite confusion.
Our true nature could be compared to the sky, and the confusion of the ordinary mind to clouds. Some days the sky is completely obscured by clouds. When we are down on the ground, looking up, it is very difficult to believe that there is anything else there but clouds. Yet we have only to fly in a plane to discover above the clouds a limitless expanse of clear blue sky. From up there, the clouds we assumed were everything seem so small and so far away down below.
We should always try to remember: The clouds are not the sky and do not “belong” to it. They only hang there and pass by in their slightly ridiculous and nondependent fashion. And they can never stain or mark the sky in any way.