To Enjoy, To Use, and To Be Used: Augustine on Everything
In the opening chapters of On Christian Teaching (I.1-5), Augustine argues that everything that exists can be divided into two groups: things to be used and things to be enjoyed. "To enjoy a thing," he proposes, "is to rest with satisfaction in it for its own sake" (I.4). An object of enjoyment is not a means to some other end, it is something desired and pursued for its own sake, as an end in itself.
"With satisfaction" is a critical qualification, however. We desire and pursue many things that do not satisfy. That's idolatry. This kind of idolatry was the dynamic at work in the first transgression in Eden and in every sin since. Whenever we turn away from the one thing able to satisfy us, our natural desires become ravenous and turn on us like wolves in winter. To settle for what fails to satisfy is a form of despair; to abandon ourselves to the wolves is another. People who struggle against despair desperately search for something to pacify their voracious appetites that threaten to eat them alive, and usually end up fleeing from one idol to the next since none can save them. Hence our restless hearts.
There is, Augustine insists, only one thing we can truly enjoy--one thing we are able to rest in with satisfaction--and therefore only one thing worthy of being our ultimate object of faith and desire: "The true objects of enjoyment, then, are the Father and the Son and the Holy Spirit, who are at the same time the Trinity, one Being, supreme above all, and common to all who enjoy Him" (I.5). Everything and everyone else is to be desired according to its usefulness for enjoying of God (cf. WLC Q&A 1).
Augustine is aware that many important questions about the proper use of a thing or person remain open, and this is one of those places where a hint of Neoplatonic influence may linger in his thought. But that influence, if present, has helped him understand Scripture rightly, and the moral, political, and economic implications are rich even if tricky to draw out.
Ordinarily, when we say someone used us we usually mean they've "done us wrong" somehow. Augustine would say that what we really mean is that they've abused us. The actual problem, in other words, is not in the fact we were used by someone but in the use they made of us. To use anything (or anyone) to any other end is to use it contrary to its divinely-ordiained purpose. Even to neglect to make a proper use of whatever (or whoever) is at hand is harmful since it treats the thing as though it had no reason-for-being--no relation to or connection with God's glory.
The things we use are desirable, but our desire for them, whatever or whoever they may be, ought to be only along the lines of and insofar as they help us know and enjoy God. That use is as full and expansive as our eternal life in Christ is abundant; and it is precisely this use that makes it possible for us to have joy here and now, through faith, as we enjoy our God who gives himself to us richly, saving us from futility and despair, filling our days with meaning and purpose.