Joy is the perception of beauty, unlike happiness, which is because of something. Joy is singing of the heart, a feeling of praise.
I find that a life of little whispered words of adoration, of praise, of prayer, of worship can be breathed all through the day. One can have a very busy day, outwardly speaking, and yet be steadily in the holy Presence ... It is a life unspeakable and full of glory, an inner world of splendor within which we may live.