Let us, then, take care not to quench the Spirit. All evil actions extinguish this light: slander, offences and the like. The nature of fire is such that everything foreign to it destroys it, and everything akin to it gives it further strength. This light of the Spirit reacts in the same manner. From The Art of Prayer

How many things do we do each day that feed our sinful nature? How many things each day do we do to feed our spiritual side?