For each and every one of us, the most important thing is our state of mind.  That which feels joy or sorrow, pleasure or pain, is just our mind.  But our mind doesn’t have to simply react to things around us.  It can be steered in different directions.  You can direct yourself toward what is good, and by doing so, you get accustomed to positive thoughts.  If you direct yourself toward being negative, that also can become a habit.  If you allow yourself to become apathetic and not care much, you become insensitive and dull.  The word spiritual refers to directing or steering our mind toward something good, something noble.  Simply that.  One of the most important factors in accomplishing that goal is to know how to let ourselves be completely at ease.

Chokyi Nyima Rinpoche, Recognizing Our Natural Mind State