The best book I read in 2011 was Thinking in Tongues, by James K.A. Smith. When you find a book like this you want to read more. So now I'm reading Smith's Imagining the Kingdom: How Worship Works. Smith is interviewed here on his new book ("You Can't Think Your Way to God.").
Smith is asked: Is there a way to get spiritual know-how apart from engaging in the spiritual disciplines?
He responds: "I don't think so."
Spiritual disciplines are "habitations of the Spirit." (I love this!) They are not about showing that we are trying pursue God. Smith says: "These are gifts that the Spirit inhabits. They are rituals that God invites us into to live into the power of the Spirit. They are the way that you put on Christ."
Spiritual disciplines are "invitations to live into God's power."
(The classic, must-read book on the spiritual disciplines remains Richard Foster's Celebration of Discipline: The Path to Spiritual Growth.)