What spirits are of God, and what are not. We must love one another, because God has loved us.

¹ Most beloved, do not be willing to believe every spirit, but test the spirits to see if they are of God. For many false prophets have gone out into the world.¹

1. 4:1Try the spirits: Viz., by examining whether their teaching be agreeable to the rule of the Catholic faith, and the doctrine of the church. For as he says, (ver. 6,) He that knows God, hears us [the pastors of the church]. By this we know the spirit of truth, and the spirit of error.(Challoner)

² The Spirit of God may be known in this way. Every spirit who confesses that Jesus Christ has arrived in the flesh is of God;¹²

1. 4:2The mere fact that a claimed prophet, or a claimed message to a claimed prophet, says that Jesus is the Son of God does not mean that the prophet is true. They may say with words that Jesus is God Incarnate, but then they go on to contradict or undermine His teachings, and so, in effect, they are denying his Incarnation. For if he truly has arrived Incarnate, then why do they undermine his teachings?(Conte)
2. 4:2Every spirit which confesses, etc: Not that the confession of this point of faith alone, is, at all times, and in all cases, sufficient; but that with relation to that time, and for that part of the Christian doctrine, which was then particularly to be confessed, taught, and maintained against the heretics of those days, this was the most proper token, by which the true teachers might be distinguished form the false.(Challoner)

³ and every spirit who contradicts Jesus is not of God. And this one is the Antichrist, the one that you have heard is coming, and even now he is in the world.¹²³

1. 4:3Any kind of contradiction of the teachings of Jesus is, in effect, a denial of the Incarnation of God, even if those false teachers say with words that Jesus arrived as God Incarnate. The Antichrist, when he arrives in the distant future, will deny that Christ was God Incarnate. But many false ideas, in some way and to some degree, foreshadow the Antichrist, by contradicting or undermining various teachings of Christ. This attitude eventually leads to the arrival of the Antichrist, who denies all that is of Christ.(Conte)
2. 4:3That dissolves Jesus: Viz., either by denying his humanity, or his divinity.(Challoner)
3. 4:3He is now already in the world: Not in his person, but in his spirit, and in his precursors.(Challoner)

⁴ Little sons, you are of God, and so you have overcome him. For he who is in you is greater than he who is in the world.

⁵ They are of the world. Therefore, they speak about the world, and the world listens to them.

⁶ We are of God. Whoever knows God, listens to us. Whoever is not of God, does not listen to us. In this way, we know the Spirit of truth from the spirit of error.

⁷ Most beloved, let us love one another. For love is of God. And everyone who loves is born of God and knows God.

⁸ Whoever does not love, does not know God. For God is love.

⁹ The love of God was made apparent to us in this way: that God sent his only-begotten Son into the world, so that we might live through him.

¹⁰ In this is love: not as if we had loved God, but that he first loved us, and so he sent his Son as a propitiation for our sins.

¹¹ Most beloved, if God has so loved us, we also ought to love one another.

¹² No one has ever seen God. But if we love one another, God abides in us, and his love is perfected in us.

¹³ In this way, we know that we abide in him, and he in us: because he has given to us from his Spirit.

¹⁴ And we have seen, and we testify, that the Father has sent his Son to be the Savior of the world.

¹⁵ Whoever has confessed that Jesus is the Son of God, God abides in him, and he in God.

¹⁶ And we have known and believed the love that God has for us. God is love. And he who abides in love, abides in God, and God in him.

¹⁷ In this way, the love of God is perfected with us, so that we may have confidence on the day of judgment. For as he is, so also are we, in this world.

¹⁸ Fear is not in love. Instead, perfect love casts out fear, for fear pertains to punishment. And whoever fears is not perfected in love.¹

1. 4:18Fear is not in charity, etc: Perfect charity, or love, banishes human fear, that is, the fear of men; as also all perplexing fear, which makes men mistrust or despair of God’s mercy; and that kind of servile fear, which makes them fear the punishment of sin more than the offence offered to God. But it no way excludes the wholesome fear of God’s judgments, so often recomended in holy writ; nor that fear and trembling, with which we are told to work out our salvation. Phil. 2.12.(Challoner)

¹⁹ Therefore, let us love God, for God first loved us.

²⁰ If anyone says that he loves God, but hates his brother, then he is a liar. For he who does not love his brother, whom he does see, in what way can he love God, whom he does not see?

²¹ And this is the commandment that we have from God, that he who loves God must also love his brother.