503. The perceptivity of the Most Ancient Church lay not merely in their perceiving what good and truth were but also in the joy and delight of doing what was good. Without this joy and delight of doing what is good perceptivity is without life. They are the source of its life. The life of love and faith deriving from it, such as the Most Ancient Church possessed, is a life that comes with performing use, that is, with the good and truth that accompany use. It is from use, by way of use, and according to use,that life is imparted by the Lord. And that which is without use can have no life in it, for that which is without use is casta side. In this respect those people were likenesses of the Lord, and in their perceptivity therefore became images too. Perceptivity is knowing what good and truth are, and so knowing what is the substance of faith. Anyone who has love within him is not content just with knowing, but with doing what is good and true, that is, with engaging in a use.