32 But in the church I only know of one Image, that is the Image of the unseen God, of Which God has said: “Let us make man in Our image and Our likeness;” that Image of Which it is written, that Christ is the Brightness of His glory and the Image of His Person. In that Image I perceive the Father, as the Lord Jesus Himself has said: “He that sees Me sees the Father.” For this Image is not separated from the Father, which indeed has taught me the unity of the Trinity, saying: “I and My Father are One,” and again: “All things that the Father has are Mine.” Also of the Holy Spirit, saying that the Spirit is Christ's, and has received of Christ, as it is written: “He shall receive of Mine, and shall declare it unto you.”
Source: Sermon against Auxentius (New Advent)