174. (5) A Trinity of Persons was unknown in the Apostolic Church, but was hatched by the Nicene Council, and from that was introduced into the Roman Catholic church, and from that again into the churches separated from it. By the Apostolic church is meant the church that existed in various places not only in the time of the apostles, but also in the second and third centuries after. But at length men began to wrench the door of the temple off its hinges, and to break robber-like into its sanctuary. The temple is the church; the door is the Lord God the Redeemer; and the sanctuary His Divinity; for Jesus says:
Verily, I say unto you, he that entereth not by the door into the sheep fold, but climbeth up some other way, the same is a thief and a robber. I am the door; by Me if any man enter in he shall be saved (John 10:1, 9).
This crime was committed by Arius and his followers.  On this account a council was convoked by Constantine the Great at Nice, a city in Bithynia; and in order to overthrow the pernicious heresy of Arius it was devised, decided upon, and ratified by the members of the council that there were from eternity three Divine persons, a Father, a Son, and a Holy Spirit, to each one of whom belonged personality, existence, and subsistence, by Himself and in Himself; also that the second person, or the Son, came down and took on a Human and wrought redemption; and therefore His Human, by a hypostatic union, possesses Divinity, and through that union He has close relationship with God the Father. From that time heaps of abominable heresies about God and the person of Christ began to spring up from the earth, and Antichrists began to rear their heads and to divide God into three persons, and the Lord the Savior into two, thus destroying the temple set up by the Lord through the apostles, and this until not one stone was left upon another that was not thrown down, according to the Lord's words (Matt. 24:2), where by "the temple" not only the edifice at Jerusalem is meant but also the church, the consummation or end of which is treated of in the whole chapter.  But what else could have been expected from that council, or from those that followed, which in like manner divided the Godhead into three, and placed God in the flesh beneath them on their footstool? For by climbing up some other way they took the Head of the church away from its body; that is, they passed Him by, and mounted beyond to God the Father as to another, with the mere mention on their lips of Christ's merit, that is, that God on account of it might be merciful, and justification might thus flow into them directly with all that goes with it, namely, remission of sins, renovation, sanctification, regeneration, and salvation, and this without any meditation on man's part.