Verse 13. - Almost identical with 1 John 3:24. In verses 1-7 the apostle says that confession of the Incarnation proves possession of the Spirit; and in verse 12 that love of the brethren proves the indwelling of God. He now (verse 13) goes on to say that possession of the Spirit proves the indwelling of God; and (verse 15) that confession of the Incarnation proves the same. So that these four facts - confession of the Incarnation, possession of the Spirit, love of our fellow-men, and indwelling of God - mutually involve one another. St. John does not say, "He has given us his Spirit," but "of his Spirit ἐκ τοῦ Πνεύματος αὐτοῦ." It is impossible for us to receive more than a portion; the fullness of the Spirit is possessed by Christ alone. In John 1:16 we have a similar use of ἐκ (comp. John 12:3).

4:7-13 The Spirit of God is the Spirit of love. He that does not love the image of God in his people, has no saving knowledge of God. For it is God's nature to be kind, and to give happiness. The law of God is love; and all would have been perfectly happy, had all obeyed it. The provision of the gospel, for the forgiveness of sin, and the salvation of sinners, consistently with God's glory and justice, shows that God is love. Mystery and darkness rest upon many things yet. God has so shown himself to be love, that we cannot come short of eternal happiness, unless through unbelief and impenitence, although strict justice would condemn us to hopeless misery, because we break our Creator's laws. None of our words or thoughts can do justice to the free, astonishing love of a holy God towards sinners, who could not profit or harm him, whom he might justly crush in a moment, and whose deserving of his vengeance was shown in the method by which they were saved, though he could by his almighty Word have created other worlds, with more perfect beings, if he had seen fit. Search we the whole universe for love in its most glorious displays? It is to be found in the person and the cross of Christ. Does love exist between God and sinners? Here was the origin, not that we loved God, but that he freely loved us. His love could not be designed to be fruitless upon us, and when its proper end and issue are gained and produced, it may be said to be perfected. So faith is perfected by its works. Thus it will appear that God dwells in us by his new-creating Spirit. A loving Christian is a perfect Christian; set him to any good duty, and he is perfect to it, he is expert at it. Love oils the wheels of his affections, and sets him on that which is helpful to his brethren. A man that goes about a business with ill will, always does it badly. That God dwells in us and we in him, were words too high for mortals to use, had not God put them before us. But how may it be known whether the testimony to this does proceed from the Holy Ghost? Those who are truly persuaded that they are the sons of God, cannot but call him Abba, Father. From love to him, they hate sin, and whatever disagrees with his will, and they have a sound and hearty desire to do his will. Such testimony is the testimony of the Holy Ghost.Hereby know we that we dwell in him, and he in us,.... That there is a communion between God and us, and a communication of his love and grace to us, and an exercise of grace upon him; for God dwells in his people by his Spirit and grace, and they dwell in him by the exercise of faith and love upon him: and this is known,

because he hath given us of his Spirit: not of the essence and nature of the Spirit, which is the same with the nature of the Father and of the Son, and is incommunicable; but either of the gifts of the Spirit, which are divided to every man as he pleases, and which being bestowed on men, and used by them, for the profit and advantage of the church of God, show that God is with them, and dwells among them of a truth; or of the graces of the Spirit, such as faith, hope, and love, which are each the gifts of God; and these being bestowed and exercised, are proofs of the mutual indwelling of God and his people; See Gill on 1 John 3:24.