Historical Confessions About the Trinity

The Westminster Confession of Faith (1646), Chapter II, Paragraph III. "In the unity of the Godhead there be three Persons of one substance, power, and eternity: God the Father, God the Son, and God the Holy Ghost. The Father is of none, neither begotten nor proceeding; the Son is eternally begotten of the Father; the Holy Ghost eternally proceeding from the Father and the Son."

The Westminster Larger Catechism, Question 9, "How many persons are there in the Godhead?  Answer: There be three persons in the Godhead, the Father, the Son, and the Holy Ghost; and these three are one true, eternal God, the same in substance, equal in power and glory; although distinguished by their personal properties."

The Westminster Shorter Catechism, Question 6, "How many persons are there in the godhead?  Answer: There are three persons in the Godhead; the Father, the Son, and the Holy Ghost; and these three are one God, the same in substance, equal in power and glory."

The Augsburg Confession (1530), by Philip Melanchthon, Article I, "there is one Divine Essence which is called and which is God: eternal, without body, without parts, of infinite power, wisdom, and goodness, the Maker and Preserver of all things, visible and invisible; and yet there are three Persons, of the same essence and power, who also are coeternal, the Father the Son, and the Holy Ghost. And the term "person" they use as the Fathers have used it, to signify, not a part or quality in another, but that which subsists of itself."

The Second Helvetic Confession (Heinrich Bullinger, 1562), Chapter III, " : 

God Is One. We believe and teach that God is one in essence or nature, subsisting in himself, all sufficient in himself, invisible, incorporeal, immense, eternal, Creator of all things both visible and invisible, the greatest good, living, quickening and preserving all things, omnipotent and supremely wise, kind and merciful, just and true. Truly we detest many gods because it is expressly written: "The Lord your God is one Lord" (Deuteronomy 6:4). "I am the Lord your God. You shall have no other gods before me" (Exodus 20:2-3). "I am the Lord, and there is no other god besides me. Am I not the Lord, and there is no other God beside me? A righteous God and a Savior; there is none besides me" (Isaiah 45:5, 21). "The Lord, the Lord, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness" (Exodus 34:6).

God Is Three. Notwithstanding we believe and teach that the same immense, one and indivisible God is in person inseparably and without confusion distinguished as Father, Son and Holy Spirit so, as the Father has begotten the Son from eternity, the Son is begotten by an ineffable generation, and the holy Spirit truly proceeds from them both, and the same from eternity and is to be worshipped with both.

Thus there are not three gods, but three persons, cosubstantial, coeternal, and coequal; distinct with respect to hypostases, and with respect to order, the one preceding the other yet without any inequality. For according to the nature or essence they are so joined together that they are one God, and the divine nature is common to the Father, Son and Holy Spirit.

For Scripture has delivered to us a manifest distinction of persons, the angel saying, among other things, to the Blessed Virgin, "The Holy Spirit will come upon you, and the power of the Most High will overshadow you; therefore the child to be born will be called holy, the Son of God" (Luke 1:35). And also in the baptism of Christ a voice is heard from heaven concerning Christ, saying, "This is my beloved Son" (Matthew 3:17). The Holy Spirit also appeared in the form of a dove (John 1:32). And when the Lord himself commanded the apostles to baptize, he commanded them to baptize "in the name of the Father, and the Son, and the Holy Spirit" (Matthew 28:19). Elsewhere in the Gospel he said: "The Father will send the Holy Spirit in my name" (John 14:26), and again he said: "When the Counselor comes, whom I shall send to you from the Father, even the Spirit of truth, who proceeds from the Father, he will bear witness to me," etc. (John 15:26). In short, we receive the Apostles' Creed because it delivers to us the true faith.

Heresies. Therefore we condemn the Jews and Mohammedans, and all those who blaspheme that sacred and adorable Trinity. We also condemn all heresies and heretics who teach that the Son and Holy Spirit are God in name only, and also that there is something created and subservient, or subordinate to another in the Trinity, and that their is something unequal in it, a greater or a less, something corporeal or corporeally conceived, something different with respect to character or will, something mixed or solitary, as if the Son and Holy Spirit were the affections and properties of one God the Father, as the Monarchians, Novatians, Praxeas, Patripassians, Sabellius, Paul of Samosata, Aetius, Macedonius, Anthropomorphites, Arius, and such like, have thought."