What is joy?

David Richo continues to tell us that "Mary is a personification of a sanctity that may happen in us in a variety of ways. Sanctity is in an unencumbered single-heartedness. That is joy. We embody in daily life the abiding powers in the divine Self, love, wisdom, and healing influence--the same qualities we have revered in Christ and the saints. That is joy. It is in receiving with gratitude the graces that make all this possible. That is joy."