What is perichoresis?

God, dwelling in the unapproachable light, is Father, Son and Holy Spirit; a community of essence, a community of moral nature and character, a community of life both in principle and continuous activity — a community of fellowship peculiar to themselves, known only to themselves and enjoyed only by themselves; and that jointly and co-equally. It is an eternal fellowship, abiding, unchangeably the same from everlasting to everlasting, an eternally mutual and reciprocal fellowship.

"There never was a moment when God was incomplete, as He would have been without Son or Spirit. The whole three Persons are co-equal. God would be still incomplete if Son or Spirit were not in everything 'such as the Father is' … The union of the Three is not one of barren necessity. It is a free and living union in which all are bound together by an absolute outpouring of each to other in love. We may think of the joy which the Father has in giving—in communicating without reserve to the Son 'all the fulness' (Col. 1:19) of His being … and it is the joy of the Son to receive—to feel the infinite flow of the Father's love concentrated in Himself, and … the gladness with which He welcomes most those wishes of the Father which will cost most to Himself … It is the glory of them all to be One … by a moral living for and in each other, in a mutual devotion such as serves as an example for men." (emphasis ours,),

"There is but one cognition in the Divine being, although the Father, the Son, and the Spirit partake in the cognition in different ways… This it is which makes, we may say, the true oneness in the Eternal Trinity. God is love: and the union of the Three is not one of barren necessity. It is a free and living union in which all are bound together by an absolute outpouring of each to other in love. We may think of the joy which the Father has in giving—in communicating without reserve to the Son, 'all the fulness' (Col. 1:19) of His being … and finding it all the more His own because lavished freely on the Only Begotten. And it is the joy of the Son to receive—to feel the infinite flow of the Father's love concentrated in Himself; and in the gratitude which must always be a part of filial love we may understand, to some extent, the gladness with which He welcomes most those wishes of the Father which will cost most to Himself, (the joy) with which He reflects that He mixes nothing of His own with what the Father gives Him."

Both instruction and blessing may be found in the perusal of, and meditation on, the following remarks upon the above scriptures. "We have, first, the absolute and essential unity of the Father and the Son, which makes them One in all that they are essentially, and [in] what flows from it. Then, mutuality of being in one another, the source and object of joy and blessing in an ineffable way. Thirdly, display — the Father in the Son. (Compare John 14.) To the first answers the whole absorbed mind and action of the disciples in the power of the Holy Ghost; to the second, that into which all were brought by the Holy Ghost; to the third, the perfect display of glory in all the saints­ Christ (in whom the Father was) in them, and here no difference — all appear loved as (kathos) Christ was loved."

The spring and source of all is in the Father's love, but the relationship itself is in the Son. This excludes, in His glorious Person, all thought of generation, offspring or subordination. Such thoughts are not consistent with the co-existence, mutuality and co-equality of that God Who is One yet God all Three. "I and the Father are One," and again, "I am in the Father and the Father is in Me," (John 10:30; John 14:10), speak of the relations and intimacies of Godhead, from eternity to eternity, yet spoken in Manhood in time, by the Son. In coming out to reveal, He is Himself what He reveals, and being Man, while still abiding in the unity of Godhead, all the blessed joys and affections proper to the filial relation are His without a break, in the Manhood He took. In this way the communications that belong to the relationship, in its heavenly and eternal blessedness, is brought before us from the Son's own lips, in the seventeenth chapter of John. There, God the Spirit records, through John, the words of the incarnate Son in His prayer to the Father, and as units in the great aggregate that was before Him in that prayer we are privileged to listen and adore and to link ourselves with the home of Divine Love, and the counsels of eternity from which all has come.

Being One in nature, substance and essential being, they love necessarily the same things and so have the same thoughts, will and purpose about everything, though each having His distinct part in activity and relationship in all that the Triune God does, but always working together in complete unison carrying out one common purpose and will. Thus of Christ, the incarnate Son, we read: "For in Him dwelleth all the fulness of the Godhead bodily." "Believest Thou not that I am in the Father, and the Father in Me? the words that I speak unto you I speak not of Myself: but the Father that dwelleth in Me, He doeth the works." "My Father worketh hitherto, and I work." "And Jesus returned in the power of the Spirit into Galilee." "I cast out devils by the Spirit of God." "Who through the eternal Spirit offered Himself without spot to God" (Col. 2: 9, John 14: 10; John 5: 17; Luke 4: 14; Matt. 12: 28; Heb. 9: 14). Each Person of the Godhead takes part in what He, the incarnate Son, does. (John 1: 14; 1 John 5: 20; 1 John 3: 8).

But this is not all. The Holy Ghost dwelling in us, we know that we are in Christ. "At that day ye shall know that I am in my Father, and ye in me, and I in you." It is not "the Father in me [which, however, was always true], and I in him" — words, the first of which, here omitted, expressed the reality of His manifestation of the Father here on earth. The Lord only expresses that which belongs to His being really and divinely one with the Father — "I am in my Father." It is this last part of the truth (implied, doubtless, in the other when rightly understood) of which the Lord here speaks. It could not really be so; but men might imagine such a thing as a manifestation of God in a man, without this man being really such — so truly God, that is to say, in Himself — that it must also be said, He is in the Father. People dream of such things; they speak of the manifestation of God in flesh. We speak of God manifest in the flesh. But here all ambiguity is obviated — He was in the Father, and it is this part of the truth which is repeated here; adding to it, in virtue of the presence of the Holy Ghost, that while the disciples should indeed fully know the divine Person of Jesus, they should moreover know that they were themselves in Him. He who is joined to the Lord is one spirit. Jesus did not say that they ought to have known this while He was with them on earth. They ought to have known that the Father was in Him and He in the Father. But in that He was alone. The disciples, however, having received the Holy Ghost, should know their own being in Him — a union of which the Holy Ghost is the strength and the bond. The life of Christ flows from Him in us. He is in the Father, we in Him, and He also in us, according to the power of the presence of the Holy Ghost.

Every true believer has his place before the Father in the Son, and the Son in every true believer by the Spirit, even as the Son of God said to His disciples, “At that day ye shall know that I am in my Father, and ye in me, and I in you” (John 14:20). We now know the Son, in this the Spirit’s day, as essentially one with the Father in the unity of the Godhead, and one with Him in all His thoughts and activities of grace for the blessing of those He has given to His Son. According to this grace, we are in the Son as having the life of the Son, and the Son is in us that His life might be manifested in testimony in this world.

The Son was in the Father as one with Him in the fulness of the Godhead, one with Him in all His counsels of love and grace, and one with Him in all the activities that would give effect to His eternal purpose, and secure those that the Father had given Him to be His companions in His own house for evermore. This was the place rightly belonging to the Son who dwelt in the Father's bosom, and who was the object of the Father's affections whether in eternity or in Manhood. As being in the Father He was one with Him in all His desires, thoughts, feelings and movements; and the resources, power and attributes of the Godhead belonged to the Son as to the Father.

But we cannot have the Son without having the Father. He who had seen Him had seen the Father; and consequently he who had communion with the Son had communion with the Father; for their thoughts and feelings were all one. He is in the Father, and the Father in Him. We have fellowship therefore with the Father. And this is true also, when we look at it in another aspect. We know that the Father has entire delight in the Son. Now He has given us, by revealing the Son, to take our delight in Him also, feeble as we are. I know, when I am delighting in Jesus — in His obedience, His love to His Father, to us, His single eye and purely devoted heart — I have the same feelings, the same thoughts, as the Father Himself. In that the Father delights, cannot but delight, in Him in whom I now delight, I have communion with the Father. So with the Son in the knowledge of the Father. All this flows, whether in the one or the other point of view, from the Person of the Son. Herein our joy is full. What can we have more than the Father and the Son? What more perfect happiness than community of thoughts, feelings, joys, and communion, with the Father and the Son, deriving all our joy from themselves? And if it seem difficult to believe, let us remember that, in truth, it cannot be otherwise: for, in the life of Christ, the Holy Ghost is the source of my thoughts, feelings, communion, and He cannot give thoughts different from those of the Father and the Son. They must be in their nature the same. To say that they are adoring thoughts is in the very nature of things, and only makes them more precious. To say that they are feeble and often hindered, while the Father and the Son are divine and perfect, is, if true, to say the Father and the Son are God, are divine, and we feeble creatures. That surely none will deny. But if the blessed Spirit be the source, they must be the same as to nature and fact.