Evil cannot be a nature. Every nature is either act or potency or a. composite of the two. Whatever is act, is a perfection and is good in its very concept. And what is in potency has a natural appetite for the reception of act; but what all beings desire is good. Therefore, too, what is composed of act and potency participates in goodness to the extent that it participates in act. And potency possesses goodness inasmuch as it is ordained to act; an indication of this is the fact that potency is esteemed in proportion to its capacity for act and perfection. Consequently no nature is of itself an evil.
Likewise, every being achieves its fulfillment according as it is realized in act, for act is the perfection of a thing. However, neither of a pair of opposites achieves fulfillment by being mixed with the other, but is rather destroyed or weakened thereby. Therefore evil does not realize its full capacity by sharing in good. But every nature realizes its full capacity by having existence in act; and so, since to be good is the object of every being’s natural tendency, a nature achieves fulfillment by participating in good. Accordingly no nature is an evil.
Moreover, any nature whatever desires the preservation of its being, and shuns destruction to the full extent of its power. Consequently, since good is that which all desire, and evil, on the contrary, is that which all shun, we must conclude that for any nature existence is in itself good, and non-existence is evil. To be evil, however, is not good; in fact, not to be evil is included in the notion of good. Therefore no nature is an evil.
St. Thomas Aquinas. (1265-1274). Compendium Theologiae: Impossibility of an Evil Nature, trans. by Cyril Vollert. St. Louis & London: B. Herder Book Co., 1947
All scripture is given by inspiration of God and is profitable for doctrine, reproof, correction, and instruction in righteousness (2 Timothy 3:16).