Catena Aurea, Pentecost, Jn 15:26-27; 16:12-15
St. Augustine (354-430): As if He said, “Seeing Me, they hated and killed Me; but the Paracleteshall give such testimony concerning Me as shall make them believe, though they see Me not.” And because He shall testify, you shall testify also: And you also shall bear witness; He will inspire your hearts, and you shall proclaim with your voices. And you will preach what you know, Because you have been with Me from the beginning; which now you do not do, because you have not yet the fullness of the Spirit. But the love of God shall then be shed abroad in your hearts by the Spirit which shall be given you, and shall make you confident witnesses to Me. The Holy Spirit by His witness made others witness, taking away fear from the friends of Christ’s, and converting the hatred of His enemies into love.
Didymus the Blind (313-398): The Holy Spirit He calls the Comforter, a name taken from His office, which is not only to relieve the sorrows of the faithful, but to fill them with unspeakable joy. Everlasting gladness is in those hearts, in which the Spirit dwells. The Spirit, the Comforter, is sent by the Son, not as Angels, or Prophets, or Apostles, are sent, but as the Spirit must be sent which is of one nature with the Divine wisdom and power that sends Him. … The Holy Spirit is not sent by the Son, and proceeds from the Father, in the sense of change of place. For as the Father’s nature, being incorporeal, is not local, so neither has the Spirit of truth, Who is incorporeal also, and superior to all created things, a local nature.
St. Augustine (354-430): While in the body we cannot know all the truth, as the Apostle says, Weknow now in part (1 Cor 13); but the Holy Spirit sanctifying us fits us for enjoying that fullness of which the same Apostle says, Then face to face. Our Lord’s promise, But when He the Spirit of truth shall come, He shall teach you all truth, or shall lead you into all truth, does not refer to this life only, but to the life to come, for which this complete fullness is reserved. The Holy Spirit both teaches believers now all the spiritual things which they are capable of receiving, and also kindles in their hearts a desire to know more.