“Why do you boast in evil, O mighty man”?
(Ps 51:3 Septuagint)

That is, he that in malice is mighty, why does he glory?
There is need that a man be mighty, but in goodness, not in malice.
Is it any great thing to glory in malice?
To build a house belongs to a few men; any ignorant man you please can tear it down.
To sow wheat, to dress the crop, to wait until it ripen, and in that fruit on which one has labored to rejoice, belongs to a few men;
with one spark any man you please can burn all the crop.
To breed an infant, when born to feed him, to educate, to bring him on to youth’s estate, is a great task;
to kill him in one moment of time any one you please is able.
Therefore those things which are done for destruction are most easily done.
“He that glories, let him glory in the Lord” (1 Cor 1:31 ). He that glories, let him glory in goodness.
You glory because you are mighty in evil…
You are about to kill a man; this thing also a scorpion, a fever, a poisonous fungus can do.
To this is your mightiness reduced, that it be made equal to a poisonous fungus?
St. Augustine, commentary on the Psalms