Augustine of Hippo : "Every one that doeth sin, doeth also iniquity." Let no man say, Sin is one thing, iniquity another: let no man say, I am a sinful man, but not a doer of iniquity. For, "Every one that doeth sin, doeth also iniquity. Sin is iniquity." — Ten Homilies on 1 John 4 Bede : Everyone who commits sin also practices lawlessness. Let no one say: sin is one thing, lawlessness another. Let no one say: I am a sinner but not lawless. For everyone who commits sin also practices lawlessness, because sin is lawlessness. The meaning of this statement is more easily understood in the Greek language in which the Epistle was written, for among them lawlessness is called ἀνομία, which means something done against or without the law, as the Greek term for law is νόμος. Therefore, when John says that everyone who commits sin also practices lawlessness, that is ἀνομία, and sin is lawlessness, he clearly indicates that whatever sin we commit is against the law of God, as the Psalmist says: "I have considered all the sinners of the earth to be apostates" (Psalms 118). For all who sin are guilty of transgression, that is, not only those who scorn the knowledge of the written law given to them but also those who corrupt the innocence of the natural law we all received in our first parent, whether through weakness, negligence, or even ignorance. Moreover, the Latin term corresponds to the same reasoning since iniquity is called as if it is contrary to equity, and whoever commits sin also practices iniquity, and sin is iniquity. Because whoever sins clearly exists in opposition to the equity of divine law by sinning. However, lest we who cannot be entirely free from sins and iniquities lose all hope of salvation, let us see what follows about the Lord: — Commentary on the Catholic Epistles Hilary of Arles : John says that sin and iniquity are the same thing, though there were heretics who denied this. According to some of them, iniquity was a crime deliberately committed, but sin was a fact of nature and therefore not a crime. — INTRODUCTORY COMMENTARY ON 1 JOHN Oecumenius : Everyone who commits sin also commits iniquity, and sin is a transgression of the law. Confirmed in the previous discourse about righteousness from the good of righteous, now also takes on demonstration from the opposites and those things that happen to them, and says: "Everyone who sins." Saying something like this: You who have been adopted, do righteousness, nor present yourselves idle in this. For just as in sin it is not he who has done or will do it, that one is called a transgressor or a sinner, but he who clings to evil and is its operator: so too the righteous one is not called he who accomplishes nothing, or the lazy one, but the diligent. It should be noted, however, that sin (αμαρτία) is indeed a fall from that which is good; iniquity (ἀνομία), on the other hand, is a transgression against the established law. And both of these have their origin: namely, sin is an erosion from that which is good; whereas iniquity is to commit an offense against the established law. They agree among themselves and are concerned with the same thing. For he who sins strays from the goal that is according to nature and in nature itself: for the goal of human nature is to live according to reason, so that it is far removed from foolishness. Similarly, he who acts unjustly transgresses the law given in nature, affected by greed. Therefore, the disciple of the Lord rightly transformed both into the same. — Commentary on 1 John