1 John 3:8

He that doeth sin

(ο ποιων την αμαρτιαν). "He that keeps on doing sin" (the habit of sin).Of the devil

(εκ του διαβολου). In spiritual parentage as Jesus said of the Pharisees in John 8:44. When one acts like the devil he shows that he is not a true child of God.Sinneth from the beginning

(απ' αρχης αμαρτανε). Linear progressive present active indicative, "he has been sinning from the beginning" of his career as the devil. This is his normal life and those who imitate him become his spiritual children.That he might destroy

(ινα λυση). Purpose clause with ινα and the first aorist active subjunctive of λυω. This purpose (εις τουτο) Jesus had and has. There is eternal conflict, with final victory over Satan certain.