1 John 4:4

Ye are of God, little children
This, with what follows, is said for the comfort of the saints, and to deliver them from the fears of being drawn aside by the delusions of the false prophets, and antichrists; since they belonged to God, were his elect, and therefore could not be finally and totally seduced; they were the children of God by adopting grace, and could not become the servants of men; they were born of God, and so were kept by the power of God unto salvation, as all that are begotten unto a lively hope are; they were enlightened by the Spirit of God, and had a discerning of truth from error, and therefore could not be imposed upon:

and have overcome them;
the false prophets, being in a good cause, fighting the good fight of faith, and having good weapons, particularly the sword of the Spirit, which is the word of God, and invincible arguments from thence; and also gracious assistance from the Spirit of God, who gives a mouth that none can shut, and wisdom that none can resist; as well as an inward experience of the truth, and power of Gospel doctrines: a testimony within themselves, which will stand the whole shock and opposition of the enemy: the Vulgate Latin version reads, "and have overcome him"; antichrist, whose spirit was then in the world; or the world itself, or Satan, the god of the world; and so the Ethiopic version reads, "and have overcome the evil one", as in ( 1 John 2:13 1 John 2:14 ) ; the reason of which victory, and which adds to the comfort and support of saints in their present warfare, is,

because greater is he that is in you, than he that is in the world;
by "he that is in the world" is meant either the devil, the prince and god of the world, and who goes up and down in it, dwells in the hearts of the men of it, under whose influence they are, and in whom he works effectually; or antichrist, whose spirit was now in the world, and whose doctrine was propagated by the false teachers, in whom he began to appear; but he that is in the saints, either God who dwells in them, and their in him, ( 1 John 4:15 ) ; is mightier than the man of sin, and his emissaries, to keep and preserve from all corruptions, and every false way; or Christ, who dwells in their hearts by faith, and is stronger than the strong man armed, and able to save and deliver out of his hands; or the Spirit of God; and so the Arabic version reads, "the Spirit that is in you"; who is in the saints, as a spirit of regeneration and sanctification, as a spirit of adoption, and the earnest of their inheritance; he is able to carry on the work of grace in them, and finish it, and will do it; and he, as a spirit of truth, is more powerful than the spirit of error; and when the enemy comes in like a flood, or pours in a flood of errors and heresies, he lifts up a standard against him, causes him to fly, and secures the saints from being carried away with it: compare with this the Septuagint version of ( Psalms 124:1 Psalms 124:2 ) , "if it had not been the Lord who was on our side"; which render it thus, "if the Lord had not been in us".