Church FathersWhither shall I go from thy spirit? Or whither shall I flee from thy face? If I ascend into heaven, thou art there; if I descend into hell, thou art present.  If I take my wings early in the morning, and dwell in the uttermost parts of the sea (Ps. 138).

But the Holy Spirit was not in heaven only; He was not absent from earth; and neither would the Son so ascend into heaven as to forsake the earth; neither did the Father alone possess the throne of Heaven, whither the Son is said to return, and whence the Holy Ghost is said to come.

For the most blessed prophet makes this acknowledgement to the Father…. If I take wings in the morning, he says, etc. … What manner then of wings has he? The soul of the believer takes to itself wings of faith, so that raised above earthly things, and dwelling wholly in the spirit, it can comprehend, with all the saints, what is the breadth, and length, and height, and depth of the knowledge of God (Eph. 3:18, 19).

[…] Whither shall I go, he says, from Thy Spirit?  From Thy Paraclete, that is, Whose fulness the Apostles receiving made known through the mouth of Peter the fulfilment of the divine promise, proclaiming: This is what was spoken of by the prophet Joel: and in the last days I shall pour out my Spirit upon all flesh (Acts 2:16, 17). And whither shall I flee from thy face?

From the Son, therefore, Who is the Face of the Father; since the Father is seen in the Son, according to the words of Our Lord and Saviour Himself, Who when Philip besought Him:

Lord, show us the Father, and it is enough for us, so answered…: Philip, he that seeth me seeth the Father also. How sayest thou, Shew us the Father? Do you not believe that I am in the Father, and the Father in me? (John 14:9).

Neither must the Holy Spirit be regarded as separated from the Father, Whose Spirit He is, nor the Son be believed to be separated from Him Whose Face He is, and Right Hand, and Power, and Wisdom.

He does not say: “If I ascend into heaven Thy Spirit is there, or Thy Face and Thy Spirit are there”, but Thou, He says, art present; and with Thy Son and with the Holy Ghost; for one and the same everywhere and forever is the divinity of the ever adorable Trinity.

But so that a clear faith and separate belief in the Father, Son, and Holy Ghost might be given to those who believe, it is accordingly written that the Father sends both the Son and the Holy Ghost; since neither He Who sends nor He Who is sent can be believed to be God, if there is a place where He is, and a place where He is not.

Gaudentius of Brescia (d. 410): Sermon 20, translated by M.F. Toale, D.D. @ Lectionary Central.