Chapter II.
In all the sacraments, it can be observed the activity of the Trinity and the equality of the divine persons, where incidentally the error of the Arians is exposed.
Therefore, having received the sacraments, you have fully understood everything that you were baptized in the name of the Trinity. In all that we have done, the mystery of the Trinity has been preserved. Everywhere, there is the Father and the Son and the Holy Spirit, one operation, one sanctification, although some things may seem special.
How? God who anointed you, and sealed you, and placed the Holy Spirit in your heart (II Cor. I, 21, 22). Therefore, you have received the Holy Spirit in your heart. Receive another, for just as the Holy Spirit is in the heart, so Christ is also in the heart. How? You have this in the Song of Songs, Christ saying to the Church: Set me as a seal upon your heart, as a seal upon your arm (Can. VIII. 6).
Therefore God anointed you, Christ marked you. How? Because you were marked with the form of his cross, with his passion: you received the seal in his likeness; so that you may rise in his form, live in his image, who was crucified for sin and lives for God: and your old self, immersed in the font, was crucified for sin, but rose again for God (Rom. VI, 4 and following).
Then you have elsewhere something special, that God has called you, but in baptism you are crucified with Christ as if specially. Then as if specially, when you receive the spiritual seal, see the distinction of persons to be, but the whole mystery of the Trinity to be interconnected.
Then what did the Apostle say to you, as it is written again? There are diversities of graces, but the same Spirit. There are diversities of ministries, but the same Lord. There are diversities of operations, but the same God, who works all in all (I Cor. XII, 4 et seq.). He says, 'God works all things.' But it is also written of the Spirit of God: 'But all these things one and the same Spirit accomplishes, dividing to each one according as He wills' (Ibid., 21). Listen to the scripture saying that the Spirit divides according to its own will, not out of obedience. Therefore, the Spirit distributes grace to you as it wants, not as it is commanded; and especially because the Spirit of God is the Spirit of Christ. And hold on to this, that it is the Holy Spirit itself, the Spirit of God itself, the Spirit of Christ itself, the Spirit of the Comforter itself.
The Arians think that they derogate from the Holy Spirit if they say that he is the Paraclete. What is the Paraclete, if not the Comforter? As if it were not also said of the Father, because he himself is the God of consolation (2 Cor. 1:3). Therefore, you see that they think that they derogate from the Holy Spirit, in whom the power of the eternal Father is proclaimed with pious affection.