It is known that there is nothing more characteristic of God than to be, because that itself which is does not belong to things which will one day end or to those which had a beginning. But that which combines eternity with the power of unending happiness could never not have been, nor is it possible that one day it will not be, because what is divine is not liable to destruction, nor does it have a beginning.

–Hilary of Poitiers, On the Trinity 1.5