I’ve seen Christians who are faithful to the church of God, who frequently demonstrate genuine enthusiasm for the things of God, and who dearly love the Word of God, trivialize their effectiveness for the Kingdom of God through lack of discipline. Spiritually they are a mile wide and an inch deep. There are no deep, time-worn channels of communing discipline between them and God. They have dabbled in everything but disciplined themselves in nothing. – Don Whitney, Spiritual Disciplines for the Christian Life.