An earthbound, earth-satisfied spirit cannot pray. In such a heart, the flame of spiritual desire is either gone out or smoldering in faintest glow. The wings of its faith are clipped, its eyes are filmed, its tongue silenced. But they, who in unswerving faith and unceasing prayer, wait continually upon the Lord, do renew their strength, do mount up with wings as eagles, do run, and are not weary, do walk, and not faint.
– EM Bounds –