And in the Holy Spirit

“And in the Holy Spirit.” What was said above at some length about Christ concerns the mystery of his becoming man and of his suffering. Because it came in between, as belonging to his person, it has somewhat delayed our mention of the Holy Spirit. Otherwise, if we take the divine nature alone into account, then just as at the beginning of the creed we say, “I believe in God the Father Almighty,” and after that, “In Jesus Christ, his only Son, our Lord,” so in the same way we add, “And in the Holy Spirit.” But all the things said above about Christ concern, as we have said, the plan by which he came in the flesh, that is, his becoming man. [a]

With the mention of the Holy Spirit the mystery of the Trinity is made complete. For just as one Father is named, and there is no other Father, and one only Son is named, and there is no other only Son, so also there is one Holy Spirit, and there cannot be another Holy Spirit. So that the persons may be told apart, the words that express their relations, their distinguishing properties, are varied. By these the first is understood to be the Father, from whom are all things, and who himself has no Father; the second, the Son, as born of the Father; and the third, the Holy Spirit, as proceeding from both and making all things holy. But so that one and the same Godhead may be set forth in the Trinity, we put the word “in” before each: as we say that we believe “in God the Father,” so also we say “in Christ his Son,” and so also “in the Holy Spirit.” But our meaning will become plainer in what follows. For the creed goes on: