You know that perfect feeling? That Life-Is-Good moment on the open highway with the windows down and the radio up, when the perfect song comes on, and you sing along with carefree, top of your lungs abandon? When joy and contentment and life well up from somewhere deep in your soul? What if you could live that way? A seventeenth-century monk named Brother Lawrence figured out how, and wrote about it in the devotional classic, The Practice of the...