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.
Whoever opens their soul to the "influx of the divine" receives the revivifying experience of a higher world order. A "spiracle of eternal life" or "window on eternity" opens up and frees the soul of too narrow a view of reality.