The Profession of Faith of the 318 Fathers

We believe in one God the Father all powerful, maker of all things both seen and unseen.  And in one Lord Jesus Christ, the Son of God, the only-begotten begotten from the Father, that is from the substance of the Father, God from God, light from light, true God from true God, begotten not made, consubstantial with the Father, through whom all things came to be, both those in heaven and those in earth; for us humans and for our salvation he came down and became incarnate, became human, suffered and rose up on the third day, went up into heavens, is coming to judge the living and the dead.  And in the holy Spirit.

And those who say "there once was when he was not," and "before he was begotten he was not," and that he came to be from things that were not, or from another hypostasis or substance, affirming that the Son of God is subject to change or alteration --- these the catholic apostolic church anathematises.