Augustine on Enjoying God

At the beginning of his work On Christian Doctrine, Augustine states that there are three categories of things: 1) things to be enjoyed, 2) things to be used, and 3) things that are to be enjoyed and used. To enjoy something, according to Augustine, is to "cling to it with love for its own sake." Therefore, the only thing that belongs to the first category is God himself. Augustine writes,

The things which are to be enjoyed are the Father, the Son, and the Holy Spirit, a single Trinity, a certain supreme thing common to all who enjoy it, if indeed, it is a thing and not rather the cause of all things, or both a thing and a cause" (On Christian Doctrine 1.4.4)