According to John 15:26, the Spirit of reality whom the Son sent from and with the Father testifies concerning the Son as the vine; hence, the Spirit testifies to the branches and through the branches to the world. In 15:26-27 the Lord Jesus said, “But when the Comforter comes, whom I will send to you from the Father, the Spirit of reality, who proceeds from the Father, He will testify concerning Me; and you testify also, because from the beginning you have been with Me.” This indicates that the Holy Spirit is the reality of all things, and we are to be witnesses of the Spirit of reality.
In these verses the Lord said that He would send to the disciples the Spirit of reality. But in 14:26 the Lord said that the Father would send the Comforter, the Holy Spirit, in the Son’s name. The Lord has two different ways of speaking about the same thing. First, in 14:26, He says that the Father will send the Spirit; now in 15:26, He says that the Lord Himself will send the Spirit. Then who sent the Spirit—the Father or the Son? We must say that the Spirit was sent by both the Father and the Son. The Father and the Son are one. The Father’s sending is the Son’s sending, and the Son’s sending is the Father’s sending. The two are one. Regardless of who it is who sends the Spirit, the Spirit is always sent with the Father and in the name of the Son. Once again we see the Triune God. When the Spirit comes, He comes with the Father in the Son’s name. So all three of the Godhead are here.
In verse 26 the Lord said that He would send the Comforter from the Father. The Greek preposition translated from in this verse is para. The sense of this preposition in Greek here is “from with.” The Spirit of reality is sent by the Son, not only from the Father but also with the Father. The Comforter comes from the Father and with the Father. The Father is the source. When the Spirit comes from the source, He does not leave the source but comes with the source. This Spirit, sent by the Son coming with the Father, will testify concerning the Son. Therefore, His testimony concerning the Son is a matter of the Triune God.
This Spirit of reality testifies concerning the Son as the vine, testifying in front of the persecuting religion (vv. 18-25). Furthermore, the Spirit testifies to the branches and through the branches to the world. Religion may persecute, but the Spirit of reality testifies that the Son is the vine. Through the believers as the branches this testimony will go forth throughout the whole world.
The Father is the source of the vine, the Son is the vine, and the Spirit is the life-juice of the vine. This great vine is the organism of the Triune God. All that the Father is, is in this organism, embodied in the vine, which is the second of the Trinity. Within the vine is the circulating life flow of the Spirit. It is the Spirit who carries the riches of the Father to sustain the vine and its branches. This vine into which we have been grafted is the organism of the Triune God.
Christ the Son is the vine, and we are the branches to bear fruit for the glorification of the Father, that is, the expression, spreading, and multiplication of the Father as its source and husbandman. All that God the Father is and has is centralized and embodied in Christ the Son, and all of this is realized in the Spirit of reality. Now all of this has been wrought into us and will be expressed and testified through us. John 15 has four very important items: God the Father as the source and founder, God the Son as the center and manifestation, God the Spirit as the reality and realization, and the branches as the Body, the corporate expression. The branches are vital, for they express what God is in Christ as the Spirit. Without the branches there can be no full expression. The full expression depends upon the branches, the Body, for what God is in Christ the Son and as the Spirit will be expressed by the branches, the Body. All that God the Father is and has is in Christ the Son, all that the Son is and has is realized as the Spirit, and all that the Spirit has is in the Body, in the church, in us. In other words, God the Father as the source is embodied in God the Son as the center who is now realized as God the Spirit as the reality. All that the Spirit has is expressed in us, that is, in the branches, the church. The Triune God in Christ is expressed, manifested, and glorified in the church.