Getting closer to the complete set of seven, this one comes in at number five on the list of cardinal sins ~ spiritual gluttony. This is the other side of moderation. It is the soul who desires so much to feel the pleasure of being in the presence of God, they nearly speed up the process and almost kill themseleves with spiritual exercises.
People dealing with spiritual gluttony will try to subdue their own flesh. Have you ever had some sin in your life and you tried to pray, read the bible, fast, etc., to remove the sin? The problem with this approach is it’s self-centeredness.
God offers grace.
John of the Cross comments that "the feelings we receive from our devotional life are the least of its benefits. The invisible and unfelt grace of God is much greater."
For more info on this series look back a couple posts to Dark Night.