Prayer is the most holy exercise of the soul

                   
"Prayer is the breath of the soul. It is the secret of spiritual power. No other means of grace can be substituted, and the health of the soul be preserved. Prayer brings the heart into immediate contact with the Well-spring of life, and strengthens the sinew and muscle of the religious experience. Neglect the exercise of prayer, or engage in prayer spasmodically, now and then, as seems convenient, and you lose your hold on God. The spiritual faculties lose their vitality, the religious experience lacks health and vigor." -  Gospel Worker  254.4.