This is long but so worth it.
When this reason, which is so just and apt—namely, that the goodness of God should create good things—is carefully considered and devoutly weighed, it puts an end to all controversies on the part of those who inquire about the origin of the world. Certain heretics, however, have not been willing to accept this reason. In their view, there are too many things—such as fire, cold, wild beasts, and the like—which are unsuited to the needy and frail mortality of this flesh (which itself stems from just punishment), and which actually do it harm. These heretics do not notice how flourishing such things are in their rightful places and in their own natures, or with what ordered beauty they are arranged, or how much they contribute, each according to its own share of beauty, to the whole scheme of things, as if to the common well being of all, or how much they actually work to our own benefit, if only we make appropriate and intelligent use of them. Even poisons, which are fatal when used wrongly, are turned into healing medicines when properly employed; and, on the other hand, even things that give us delight, such as food and drink and sunlight, are seen to be harmful when immoderately or improperly used. In this way, divine providence warns us not to blame things without thought but rather to inquire diligently into their usefulness. And when our insight or our weakness fails us, whe should believe that teheir usefulness is simply obscure, as were various other things that we have barely been able to discover. The very fact that a thing's usefulness is hard to find, in fact, serves us either as an exercise in humility or as an antidote to pride. For there is no nature whatsoever that is evil; in fact, "evil" is nothing but a term for the privation of good.
St. Augustine, The City of God, book XI