Before the world was formed, when there was as yet no sun dividing day from night, there was not an age such as could be measured, but there was the sort of temporal motion and interval that is co-extensive with eternity. And in this sense there is but one age, and God is spoken of as AINIOS and PROAIWNIOS, for the age or æon itself is His creation. For God, Who alone is without beginning, is Himself the Creator of all things, whether age or any other existing thing. And when I say God, it is evident that I mean the Father and His Only begotten Son, our Lord, Jesus Christ, and His all-holy Spirit, our one God (John the Damascene, De Fide 2.1).
I included the part about the one God being the tripersonal God in order that I could not be accused of clipping the quote or taking it out of context.