4:1 Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world.
4:2 This is how you can recognize the Spirit of God: Every spirit that acknowledges that Jesus Christ has come in the flesh is from God,
4:3 but every spirit that does not acknowledge Jesus is not from God. This is the spirit of the antichrist, which you have heard is coming and even now is already in the world.
4:4 You, dear children, are from God and have overcome them, because the one who is in you is greater than the one who is in the world.
4:5 They are from the world and therefore speak from the viewpoint of the world, and the world listens to them.
4:6 We are from God, and whoever knows God listens to us; but whoever is not from God does not listen to us. This is how we recognize the Spirit of truth and the spirit of falsehood.
4:7 Dear friends [loved ones], let us love [Gr. agape: “self-giving that acts on behalf of others, regardless of the cost to the one loving” (Dean)] one another, for love comes from God [the source of our agape love for one another; unlike eros or phileo love, agape love does not come naturally to humans]. Everyone [those who love one another (4:7)] who loves [showing love is an evidence of salvation] has been born [cf. John 3:1-8] of God and knows [personal knowledge] God.
4:8 [conversely] Whoever does not [fails to] love [gives evidence that He does not have His nature and…] does not know God, because God is love [cf. 4:16; everything God does is an expression of His nature — thus He rules in love, He judges in love, etc.].
4:9 [How can we know for sure God loves us?] This is how God showed [the love John spoke of involved concrete and objective acts] his love among us: He sent [God’s love required Him to send Jesus] his one and only [unique, only one of the kind] Son into the world [the incarnation] that we might live through him [cf. Jn. 3:16-17].
4:10 This [refers to God’s act on our behalf in 4:9; distinguished God’s kind of love with any love claimed by the false teachers] is love: not that we loved God [as false teachers claimed], but that he loved [took the initiative; cf. Rom. 5:8] us and sent [it is possible to give without loving but it is not possible to love without giving; the true nature of love is unselfish and sacrificial] his Son as an atoning sacrifice [propitiation (offering made to appease) / expiation (forgiveness or sending away sins and guilt)] for our sins.
4:11 Dear friends, since God so loved us, we also ought to love one another [cf. Jn. 13:34-35].
4:12 No one has ever seen [some believe this is a reference to the false teachers who may have claimed visions of God] God [cf. Jn. 4:24; Ex. 33:20,23]; but [the evidence of God is seen when we show His love to others; cf. Jn. 13:35] if we love one another, God lives [abides and can be seen] in us and his love is made complete [reaches its intended purpose in our lives; this happens only when love is expressed in concrete actions] in us.
4:13 We know [are assured; have confirmation] that we live [abide] in him and he in us, because [how we know] he has given us of his Spirit [cf. Eph. 1:13-14; Holy Spirit motivates us to obey God in loving acts].
4:14 And we [testimony of the church] have seen and testify that the Father has sent his Son to be the Savior of the world.
4:15 [how the Holy Spirit comes to live in a person] If anyone acknowledges [heartfelt confession] that Jesus is the Son of God [testimony of those who are believers], God lives in him [in the person of he Holy Spirit] and he in God [members of God’s family].
4:16 And so we know [refers to knowledge of God’s love gained through experience; and because we know we…] and rely [having faith in His Son; believe, trust in, rely on the fact that God loves us] on the love God has for us. God is love. Whoever lives in [remain in, abide in] love [“Living in love means Christ is your Savior, and you need not fear the judgment” (Butler)] lives in God, and God in him.
4:17 In this way, love is made complete [has fulfilled its purpose] among us so that we will have confidence [boldness] on the day of judgment [assurance of eternal salvation; God’s love enables believers to face death with confidence], because in this world we are like him.
4:18 There is no fear [the other side of confidence] in love. But perfect [strong, mature] love drives out fear [fear of judgment], because fear has to do with punishment. The one who fears [live in fearful uncertainty of the day of judgment] is not made perfect in love [denial of God’s love and failure to trust Him].
4:19 We love [the love with which we love is not our own but the love of God in us] because he first [took the initiative (cf. 4:10)] loved us [God’s love sets us free to love others].
4:20 If anyone says, “I love God,” yet hates his brother [fellow human being or fellow Christian], he is a liar. For anyone who does not love his brother, whom he has seen, cannot love God, whom he has not seen.
4:21 And he has given us this command [cf. Jn. 13:34]: Whoever loves God must also love his brother [God’s love and Christian love are inseparable; cf. Mk. 12:30-31].