Your soul is your life. Everything else is a fiction -- a mind game in authenticity. Without nourishing your own soul, you can't nourish the world; you can't give what you don't have. As your soul grows, however, it emanates invisibly and involuntarily the light which it has received.
In any activity that requires concentrated effort, the breath quite naturally plays a role. If you have ever tried to thread a needle or repair a watch, you might have observed that without even thinking about it the breath quiets and deepens. Singers, swimmers, people who struggle with panic attacks, and a host of others learn the importance of proper breathing in order to negotiate the respective tasks at hand. Thus, that the art of contemplative practice can be facilitated by the breath should come as no surprise.