We know that whosoever is born of God sinneth not - Is not habitually and characteristically a sinner; does not ultimately and finally sin and perish; cannot, therefore, commit the unpardonable sin. Though he may fall into sin, and grieve his brethren, yet we are never to cease to pray for a true Christian: we are never to feel that he has committed the sin which has never forgiveness, and that he has thrown himself beyond the reach of our prayers. This passage, in its connection, is a full proof that a true Christian “will” never commit the unpardonable sin, and, therefore, is a proof that he will never fall from grace. Compare the notes at Hebrews 6:4-8; Hebrews 10:26. On the meaning of the assertion here made, that “whosoever is born of God sinneth not,” see the notes at 1 John 3:6-9.
Keepeth himself - It is not said that he does it by his own strength, but he will put forth his best efforts to keep himself from sin, and by divine assistance he will be able to accomplish it. Compare the 1 John 3:3 note; Jude 1:21 note.
And that wicked one toucheth him not - The great enemy of all good is repelled in his assaults, and he is kept from falling into his snares. The word “toucheth” (ἅπτεται haptetai) is used here in the sense of harm or injure.