1-john 3:8

He that committeth sin is of the devil - Hear this, also, ye who plead for Baal, and cannot bear the thought of that doctrine that states believers are to be saved from all sin in this life! He who committeth sin is a child of the devil, and shows that he has still the nature of the devil in him; for the devil sinneth from the beginning - he was the father of sin, brought sin into the world, and maintains sin in the world by living in the hearts of his own children, and thus leading them to transgression; and persuading others that they cannot be saved from their sins in this life, that he may secure a continual residence in their heart. He knows that if he has a place there throughout life, he will probably have it at death; and, if so, throughout eternity.

For this purpose - Εις τουτο· For this very end - with this very design, was Jesus manifested in the flesh, that he might destroy, ἱνα λυσῃ, that he might loose, the bonds of sin, and dissolve the power, influence, and connection of sin. See on 1 John 3:3 (note).

He that committeth sin - Habitually, willfully, characteristically.

Is of the devil - This cannot mean that no one who commits any sin, or who is not absolutely perfect, can be a Christian, for this would cut off the great mass, even according to the belief of those who hold that the Christian may be perfectly holy, from all claim to the Christian character. But what the apostle here says is true in two senses:

(1) That all who commit sin, even true believers, so far as they are imperfect, in this respect resemble Satan, and are under his influence, since sin, just so far as it exists at all, makes us resemble him.

(2) all who habitually and characteristically sin are of the devil." This latter was evidently the principal idea in the mind of the apostle. His object here is to show that those who sinned, in the sense in which it would seem some maintained that the children of God might sin, could have no real evidence of piety, but really belonged to Satan.

For the devil sinneth from the beginning - The beginning of the world; or from the first account we have of him. It does not mean that he sinned from the beginning of his existence, for he was made holy like the other angels. Notes, Jde 1:6. The meaning is, that he introduced sin into the universe, and that he has continued to practice it ever since. The word sinneth here implies continued and habitual sin. He did not commit one act of sin and then reform; but he has continued, and still continues, his course of sin. This may confirm what has been already said about the kind of sin that John refers to. He speaks of sinning habitually, continuously, willfully; and anyone who does this shows that he is under the influence of him whose characteristic it has been and is to sin.

For this purpose the Son of God was manifested - Became incarnate, and appeared among people, 1 John 3:5. Compare the notes at 1 Timothy 3:16.

That he might destroy the works of the devil - All his plans of wickedness, and his control over the hearts of people. Compare the Matthew 8:29 note; Mark 1:24 note; Hebrews 2:14 note. The argument here is, that as the Son of God came to destroy all the works of the devil, he cannot be his true follower who lives in sin.

3:8 He that committeth sin is a child of the devil; for the devil sinneth from the beginning - That is, was the first sinner in the universe, and has continued to sin ever since. The Son of God was manifested to destroy the works of the devil - All sin.And will he not perform this in all that trust in him?