1 John 3:7

The same truth stated, with the addition that he who sins is, so far as he sins, "of the devil." let no man deceive you--as Antinomians try to mislead men. righteousness--Greek, "the righteousness," namely, of Christ or God. he that doeth . . . is righteous--Not his doing makes him righteous, but his being righteous (justified by the righteousness of God in Christ, Rom 10:3-10) makes him to do righteousness: an inversion common in familiar language, logical in reality, though not in form, as in Luk 7:47; Joh 8:47. Works do not justify, but the justified man works. We infer from his doing righteousness that he is already righteous (that is, has the true and only principle of doing righteousness, namely, faith), and is therefore born of God (Jo1 3:9); just as we might say, The tree that bears good fruit is a good tree, and has a living root; not that the fruit makes the tree and its root to be good, but it shows that they are so. he--Christ.

— Jamieson-Fausset-Brown Commentary (public domain)