1 John 3:10

In this

(εν τουτω). As already shown. A life of sin is proof that one is a child of the devil and not of God. This is the line of cleavage that is obvious to all. See John 8:33-39 for the claim of the Pharisees to be the children of Abraham, whereas their conduct showed them to be children of the devil. This is not a popular note with an age that wishes to remove all distinctions between Christians and the world.Doeth not righteousness

(ο μη ποιων δικαιοσυνην). Habit (linear present participle) again of not doing righteousness, as in verse 1 John 3:7 of doing it. Cf. ποιε and μη ποιων (doing and not doing) in Matthew 7:24; Matthew 7:26.Neither

(κα). Literally, "and," but with the ellipsis of ουκ εστιν εκ του θεου (is not of God). The addition here of this one item about not loving (μη αγαπων) one's brother is like Paul's summary in Romans 13:9, a striking illustration of the general principle just laid down and in accord with 1 John 2:9-11.