If our ordinary, self-centered viewpoint is dominant, rocks and tree roots are undesirable. But if we change our point of view, then the very fact that there are rocks and tree roots makes the valley stream more beautiful and the sight of waves breaking upon them beyond description. When we perceive joy, anger, happiness and sorrow as enriching our lives, just as rocks and tree roots and water spray embellish nature, then we are able to accept whatever happens and live like flowing water, without clinging to anything.
It is one of the goals of human beings to develop to the point where life is aligned to God in such a way that we behave like an angel in complete service to heaven.