26 But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me: 27 And ye also shall bear witness, because ye have been with me from the beginning. (John 15:26-27 KJV)
William Burkitt’s Commentary
Here our Holy Lord confirms himself, that, though he had laid them under many aspersions and scandals from the world, yet all these should be done away by the coming of the Holy Spirit who should testify of him, and make his person and doctrine to be acknowledged in the world; and that they themselves should bear witness of him who had been with him from the beginning; that is, since he first began to exercise his prophetic office.
Observe here, 1. That Father, Son, and Holy Spirit, are three distinct persons in the godhead.
2. That the Holy Ghost proceedeth from the Father and the Son: here the Son is said to send him: and, as to the Father, he is said to proceed from him.
If the Holy Ghost doth not proceed from the Son, why he is called The Spirit of the Son, Galatians 4:6? Why is he said here to be sent by the Son? The Comforter whom I will send unto you from the Father. And if the Spirit doth not proceed from the Son, what personal relation can we conceive between the Son and the Spirit?
Observe, 3. That it is the highest dignity and honour of the apostles and ministers of Christ, that the Spirit beareth no testimony unto Christ, but with and according to the testimony given by them; for here it is conjoined, He shall testify of me! and ye shall also bear witness, who have been with me from the beginning.