If the Paraclete had come to testify of Himself and to do an independent work irrespective of Christ, His mission would not have conserved the memory of Christ, but would have eclipsed it. If He had come in the name of the Father to maintain the meager unity of God in the bare and simple sense taught by so called liberal Christianity, the outcome would have been the final oblivion of Jesus Christ following the denial of everything supernatural in His birth and ministry.
But He proceeded from the Father and the Son specially charged with the office of testifying of the Son, yea, of glorifying Him, not only in the gospel record, which He should inspire, and in the doctrines to be unfolded in apostolic sermons and epistles, but by His indwelling presence in the consciousness of believers, revealing Christ in them in a manner wholly indescribable but blessedly real and certain. We do not wonder at the tenacity with which western Christianity has insisted on the "Filioque" (and from the Son) in the creed respecting the procession of the Holy Ghost. This enlargement of the creed not only conserves the dignity of the Son of God and harmonizes with His Trinitarian address in John xiv. -xvi. and with other texts in which the Paraclete is called the "Spirit of Christ" (Rom. viii. 9), the "Spirit of Jesus" (Acts xvi. 7, Revised Version) and "Christ" (Eph. iii. 17), but it is confirmed by the experience of all who testify that the Comforter "has taken up His lasting abode in their hearts." (Alford). These rejoice in a wonderful magnifying of Christ and in an inexpressible increase of love to Him. If troubled before by doubts of His divinity, their doubts are forever dispelled, and "in the Holy Spirit" they gladly and spontaneously say, "Jesus is Lord" (I Cor. xii. 3, Revised Version). They are as sure of his Godhead as was Thomas in the presence of his risen Master when he exclaimed, "My Lord and my God" (John xx. 28).
— The Gospel of the Comforter, Chapter 9.