1 John 3:12

A brother's love suggests its opposite, a brother's hate, and that in the typical instance of it, the fratricide Cain.

Not as Cain, who was of that wicked one Better, as R.V., Not as Cain was of the evil one:there is no -who" in the Greek, nor any pronoun before -the evil one." Here as in John 1:21; John 1:25; John 6:14; John 6:48; John 6:69; John 7:40, the definite article has been turned into a demonstrative pronoun in A. V. See on 1 John 1:2. In -from the beginning" (1 John 3:8) S. John has gone back to the earliest point in the history of sin. The instance of Cain shewed how very soon sin took the form of hate, and fratricidal hate. It is better not to supply any verb with -not": although the sentence is grammatically incomplete, it is quite intelligible. -We are not, and ought not to be, of the evil one, as Cain was." Commentators quote the "strange Rabbinical view" that while Abel was the son of Adam, Cain was the son of the tempter. Of course S. John is not thinking of such wild imaginations: Cain is only morally-of the evil one". Here, as elsewhere in the Epistle (1 John 2:13-14; 1 John 5:18-19), S. John uses -the evil one" as a term with which his readers are quite familiar. He gives no explanation.

and slew his brother This was evidence of his devilish nature. The word for -slay" (σφάζειν) is a link between this Epistle and Revelation (Revelation 6:4, &c.; see below), occurring nowhere else in N. T. Its original meaning was -to cut the throat" (σφαγή), especially of a victim for sacrifice. In later Greek it means simply to slay, especially with violence. But perhaps something of the notion of slaying a victim clings to it here, as in most passages in Revelation (Revelation 5:6; Revelation 5:9; Revelation 5:12; Revelation 6:9; Revelation 13:3; Revelation 13:8; Revelation 18:24).

And wherefore slew he him? S. John puts this question to bring out still more strongly the diabolical nature of the act and the agent. Was Abel at all to blame? On the contrary, it was his righteousnesswhich excited the murderous hate of Cain. Cain was jealous of the acceptance which Abel's righteous offering found, and which his own evil offering did not find: and -who is able to stand before envy?" (Proverbs 27:4). Cain's offering was evil, (1) because it -cost him nothing" (2 Samuel 24:24); (2) because of the spirit in which it was offered.

and his brother's righteous The last mention of the subject of righteousness with which this section opened (1 John 2:29; comp. 1 John 3:7; 1 John 3:10). Neither -righteousness" nor -righteous" occur again in the Epistle; righteousness being merged in the warmer and more definite aspect of it, love. This is a reason for including from 1 John 2:29 to 1 John 3:12 in one section, treating of the righteousness of the children of God. Comp. -By faith Abel offered unto God a more excellent sacrifice than Cain, through which he had witness borne to him that he was righteous" (Hebrews 11:4).