Breathing is the connection between the mind and the body. When the mind concentrates on the breath, it focuses attention on the present moment. Breathing is the first step on the path to discover your spiritual nature. As you get the body to breathe correctly, the mind settles down, and that creates fertile ground to develop whatever spiritual nature exists within you.
The further one travels the spiritual path toward Home ... the more precious is one's relationship with Silence. Though spiritual disciplines may change over the course of one's journey, the one discipline which seems constant, though it ever deepens, is the friendship with Silence.