I have come to realize (with John of the Cross and others) there there is an emptiness in my heart that I constantly seek to fill -- either with little "needs" or with activity. This passion to fill betrays the fact that I do not want to face and accept my radical emptiness as a creature -- as one who is nothing but capacity for the infinite. The passion to keep filling more and more is simply a testimony that "You have made our hearts for you, and they are restless until they rest in you."
The psalmist said it long before Augustine: "In God alone is my soul at rest." (Ps 62:1) And Jesus said that in him we would find rest for our souls. Often, when I begin to pray -- that is, when I enter that space of God which is supposed to be empty of other "filler" -- I find my heart and mind rushing immediately to some "filler" -- a need unmet or an activity undone. This simply shows how much my ego fears to be empty. But empty it must be if you, Lord, are to fill it -- for that is what you want to do.
May I have the heart of Mary, empty of all and filled with the All which is you.
~George T. Montague