Third Day
The Holy Ghost is the Third Person of the Blessed Trinity: this is one of the dogmas of the Christian religion; it is the foundation of our holy faith. In God there are three divine persons, the Father, the Son, and the Holy Ghost. Each person, among created intelligences, is a distinct and a separate unity, complete, entire in itself, but by its limitation making only one individual. But in God the three divine persons have one distinct mode of subsistence, for each possesses in common the whole divine essence. The substance of God belongs to each of the three divine persons. Therefore we say that there are three divine persons in God, not three individuals; for an individual would signify a distinct nature. Accordingly, the Athanasian creed declares, “Such as the Father is, such is the Son, and such is the Holy Ghost.” The Father is God, the Son is God, and the Holy Ghost is God. Yet there are not three Gods, but only one God. In speaking of the nature of God’s being, we find ourselves necessarily beyond the power of reasoning; we only know that the infinite God is one in essence and three in person.
Prayer.
Come, Holy Ghost, fill the hearts of Thy faithful, etc., etc.