The purpose for which man was created:
One must not be without work for a single moment. But there is work performed by the body, visibly, and there is work which is done mentally, invisibly. And it is this second kind that constitutes real work. It consists primarily in the unceasing remembrance of God, with the prayer of the mind in the heart. Nobody sees it, yet those who are in this state work with ceaseless vigour. This is the one thing necessary. Once it is there, do not worry about any other work.
Theophan the Recluse, The Art of Prayer, p. 192