1 Jn 3:8 He who sins. This phrase means “who habitually practice sin” (see notes on vv. 4, 6). of the devil. The phrase gives the source of the false teachers’ actions. The term “devil” means “accuser” or “slanderer.” Not only does Satan (“adversary”) oppose God and his plan, but is the originator and instigator of sin and rebellion against God and His law (v. 4; see notes on Eph. 6:10–17). Therefore, all the unsaved are under the diabolic influence of Satan. Their sinful lifestyle reflects their satanic origin (see note on Eph. 2:1). John contrasts the children of God with the children of Satan in terms of their actions. While those who are truly born again reflect the habit of righteousness, Satan’s children practice sin. from the beginning. Since Satan was originally created as perfect and only later rebelled against God (Is. 14:12–14; Ezek. 24:12–17), John probably means the moment of his rebellion against God, the beginning of his rebellious career. Since sin characterizes him completely, so everyone characterized by sin must derive from him (cf. John 8:44). For this purpose … that He might destroy. A third reason why Christians cannot practice sin is because Christ came to destroy the works of the arch-sinner, Satan. The devil is still operating, but he has been defeated and in Christ we escape his tyranny. The day will come when all of Satan’s activity will cease in the universe and he will be sent to hell forever (Rev. 20:10). works of the devil. This summarizes a variety of the devil’s activities: sin, rebellion, temptation, ruling the world, persecution and accusation of saints, instigation of false teachers, power of death (e.g., Luke 8:12; John 8:44; Acts 5:3; 1 Cor. 7:5; 2 Cor. 4:4; Eph. 6:11, 12; 1 Thess. 2:18; Heb. 2:14; Rev. 12:10).
3:9 The fourth reason why Christians cannot practice sin is because it is incompatible with the ministry of the Holy Spirit, who has imparted a new nature to the believer (John 3:5–8). born of God. John wrote here of the new birth (John 3:7). When people become Christians, God makes them new creatures with new natures (2 Cor. 5:17). Believers have God’s characteristics because they have been born into God’s family. This new nature exhibits the habitual character of righteousness produced by the Holy Spirit (Gal. 5:22–24). John repeats this phrase twice for emphasis. His seed. The new birth involves the acquisition of a seed, which refers to the principle of life of God imparted to the believer at salvation’s new birth. John uses this image of a planted seed to picture the divine element involved in being born again. See notes on 1 Peter 1:23–25. remains. The word conveys the idea of the permanence of the new birth which cannot be reversed, for those who are truly born again are permanently transformed into a new creation (2 Cor. 5:17; Gal. 6:15; Eph. 2:10). he cannot sin. This phrase once again conveys the idea of habitual sinning (see vv. 4, 6).
3:10 This summary verse is the key to vv. 4–10. Only two kinds of children exist in the world: children of God and children of Satan. No one can belong to both families simultaneously. Either one belongs to God’s family and exhibits His righteous character or one belongs to Satan’s family and exhibits his sinful nature.


MacArthur, J., Jr. (Ed.). (1997). The MacArthur Study Bible (electronic ed., p. 1969). Nashville, TN: Word Pub.