2 Now those who became apostates are these, Arius, Achilles, Aeithales, Carpones, another Arius, and Sarmates, sometime Presbyters: Euzoïus, Lucius, Julius, Menas, Helladius, and Gaius, sometime Deacons: and with them Secundus and Theonas, sometime called Bishops. And the novelties they have invented and put forth contrary to the Scriptures are these following:— God was not always a Father, but there was a time when God was not a Father. The Word of God was not always, but originated from things that were not; for God that is, has made him that was not, of that which was not; wherefore there was a time when He was not; for the Son is a creature and a work.
Neither is He like in essence to the Father; neither is He the true and natural Word of the Father; neither is He His true Wisdom; but He is one of the things made and created, and is called the Word and Wisdom by an abuse of terms, since He Himself originated by the proper Word of God, and by the Wisdom that is in God, by which God has made not only all other things but Him also. Wherefore He is by nature subject to change and variation as are all rational creatures. And the Word is foreign from the essence of the Father, and is alien and separated therefrom.
And the Father cannot be described by the Son, for the Word does not know the Father perfectly and accurately, neither can He see Him perfectly. Moreover, the Son knows not His own essence as it really is; for He is made for us, that God might create us by Him, as by an instrument; and He would not have existed, had not God wished to create us. Accordingly, when some one asked them, whether the Word of God can possibly change as the devil changed, they were not afraid to say that He can; for being something made and created, His nature is subject to change.
Source: Deposition of Arius (New Advent)