1 John 3:7-8, “7 Little children, let no one deceive you. Whoever practices righteousness is righteous, as he is righteous. 8 Whoever makes a practice of sinning is of the devil, for the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the works of the devil.”
The Apostle John in 1 John emphasizes the importance of personal holiness. The nature of the false teaching he confronts regarding sin is a bit unclear. These false teachers thought not only could they be without sin, but that they had never sinned (1 John 1:8-10). Many Gnostics did not view acts done in the body as affecting one’s spiritual life. Even with that said, it is clear, they denied the gravity of sin in word and deed which resulted in them being liars. In 1 John 3:7-8, John warns us against these teachers linking our character with the character of Jesus Christ. All those who practice righteousness are righteous as Christ is righteous, John teaches in 1 John 3:7. This does not mean Christians are as holy in practice as Jesus. John is reminding his readers and Christians today, those in union with Jesus will be like Christ. Christians will not be perfectly holy in this life, but the regenerate person will live their lives marked by concern for personal holiness which entails a lifestyle marked by repentance.
In contrast, those whose lives are bent towards sin are of the Devil, John teaches in 1 John 3:8. Such a claim by these people is false because Jesus, the Son of God came to destroy the works of the Devil (1 John 3:8). Those who do the works of Satan oppose the Lord Jesus. Those who are in Christ, have had the power of sin broken. Also, those who belong to Jesus demonstrate this by loving holiness, instead, of sin. Christians aim, even strive, to live lives honoring to the Lord before His face, repenting, and living in gratitude for the salvation offered them by Christ.
Jesus’ death and resurrection broke the power of Satan and destroyed his evil works. Jesus secured this victory but has not fully consummated it. Even so, He has given Christians a role in destroying the works of Satan, until, the Lord Jesus returns in triumph (2 Corinthians 10:4-6). Christians fulfill this role in preaching the gospel and working hard to make disciples who make disciples (Matthew 28:18-20). They do this through evangelization, feeding the hungry, and more, all for the glory of the gospel, so disciples made be made to the glory of God.