Not without trembling, we have entreated of the most holy mystery of the reverend Trinity, the Father, the Son, and the Holy Ghost, which we have learned out of the scriptures: and here now we will stay, humbly worshipping this Unity in trinity and Trinity in unity. And let us keep in mind and acknowledge this distinction or division most manifestly declared in the scriptures, and the unity also commended unto us with exceeding great diligence…. There is but one God…. Therefore when we read that God created the world, we understand that the Father from whom are all things, by the Son by whom are all things, in the Holy Ghost in whom are all things, created the world. And when we read that the Son became flesh, suffered, died, and rose again for our salvation, we believe that the Father and the Holy Ghost, though they were not partakers of his incarnation and passion, yet notwithstanding that they wrought our salvation by the Son…. And when sins are said to be forgiven in the Holy Ghost, we believe that this benefit and all other benefits of our blessedness are unseparably given and bestowed upon us from one, only, true, living, and everlasting God, who is the Father, the Son, and the Holy Ghost. To whom be praise and thanksgiving for ever and ever. Amen.
Heinrich Bullinger (1504–1575). A Swiss reformer, and the successor of Zwingli as head of the Zurich church, Bullinger wrote both theological and historical works comprising some 127 titles. There exist about 12,000 letters from and to Bullinger, the most extended correspondence preserved from Reformation times. He corresponded with Henry VIII, Edward VI, and Elizabeth I of England, Christian II of Denmark, and Frederick III Elector Palatine among others.
From “Of The Holy Ghost: The Eighth Sermon” in “The Other Eight Sermons of the Fourth Decade” in Decades of Henry Bullinger, translated by H.I., Volume 4 (Cambridge: University Press, 1851), 325–326.