The way in which God and man in one Person are united and presented in the blessed Lord in this Epistle strikes me more and more, so that it is impossible to separate and apply them distinctively (chap. v. 20 giving the clue to it). Thus already in chap 2:5 in Whom do we know we are? All previously is Christ as such, and His word is spoken of. But “in Him” is always “in God” here, nor do I believe that it occurs to the apostle to distinguish them here. In ver. 6 it is clearly Jesus Christ, for we are to walk as He walked; and it may be taken to be Christ in ver. 5. But being “in Christ” is not the subject or tone of the Epistle as distinguishing Him. Vers. 24, 27 make “Him” in the last impossible to distinguish. Of what follows I have spoken elsewhere. In ver. 28 it is Christ, in ver. 29 it is God. In chap. iii. 1 it is God, “children of God,” but in the end of the verse Christ on earth is the same Being; in ver. 2, it is God again, but “like Him” is Christ, and we see “Him as He is.”
So chap. 3:3, 33 is clearly God—Jesus Christ is His Son; but “He” gave us commandment is Jesus Christ Himself. In ver. 24 “His” commandments are God's, and he who keeps them dwells in Him, and He in him; and He has given us His Spirit.
In chap. 4:2 it is the Spirit of God. In ver. 12 it is clearly so: God dwells in us, and this is connected with His nature. Still it is God Himself, and we dwell in Him; and it is by the Spirit we know first we dwell in Him and then He in us. But the source of it is that God dwells in us. God and Christ, verses 12 and 15, are positive revelations of the word; ver. 13 our experimental realization of it. In ver. 16 also, God being love, he that dwells in love dwells in God, and God in him. Chap. iii. 24 is the outward fact, so that the Spirit could be distinguished from evil spirits (compare 1 Cor. 12:1-3; 14:24, 251Now concerning spiritual gifts, brethren, I would not have you ignorant. 2Ye know that ye were Gentiles, carried away unto these dumb idols, even as ye were led. 3Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Ghost. (1 Corinthians 12:1‑3)
24But if all prophesy, and there come in one that believeth not, or one unlearned, he is convinced of all, he is judged of all: 25And thus are the secrets of his heart made manifest; and so falling down on his face he will worship God, and report that God is in you of a truth. (1 Corinthians 14:24‑25)). But in 1 John 3 the unity of God and Jesus as one Object before the mind is clear. There dwelling in God Comes first, and then He in us. But the testimony of the Spirit is only to Him in us to guard against false spirits which were at work. In chap. 4:17 it is clearly Christ; but it is God and His love which had been spoken of before.
As regards God's dwelling in us and we in Him, besides' chap. ii. 5 which stands by itself, we have chap. iii. 23, 24: obedience, love to one another, and faith in His Son Jesus Christ. But this brings out the practical fact that we dwell in Him and God in us, the dwelling in Him being the state of our souls, when this life is so in existence. Here, His dwelling in us is the strength of His power and presence which so belongs to us—this known to us by His Spirit given to us; and for the moment the Spirit confines Himself to this, guarding us against evil spirits.—J.N.D.