Can anyone be a father without beginning to be one? Yes, one who did not begin his existence. What begins to exist begins to be a father - God the Father did not begin at all. He is Father in the true sense, because He is not a son as well. Just as the Son is son in the true sense, because He is not a father as well. In our case, the word 'father' cannot be truly appropriate, because we must be fathers and sons.
Gregory of NazianzusAs far as we can reach, He Who Is, and God, are the special names of His Essence; and of these especially He Who Is, not only because when He spoke to Moses in the mount, and Moses asked what His Name was, this was what He called Himself, bidding him say to the people 'I Am has sent me' (Ex. 3:14), but also because we find that this Name is the more strictly appropriate.
Gregory of NazianzusWho gave you the ability to contemplate the beauty of the skies, the course of the sun, the round moon, the millions of stars, the harmony and rhythm that issue from the world as from a lyre, the return of the seasons, the alternation of the months, the demarcation of day and night, the fruits of the earth, the vastness of the air, the ceaseless motion of the waves, the sound of the wind?
Gregory of NazianzusLet us quake before the great Spirit, Who is my God, Who has made me know God, Who is God there above, and Who forms God here: almighty, imparting manifold gifts, Him Whom the holy choir hymns, Who brings life to those in heaven and on earth, and is enthroned on high, coming from the Father, the divine force, self-commandeered; He is not a Child (for there is one worthy Child of the One who is best), nor is He outside the unseen Godhead, but of identical honor.
Gregory of NazianzusIf anyone does not believe that Holy Mary is the Mother of God, he is severed from the Godhead. If anyone should assert that He passed through the Virgin as through a channel, and was not at once divinely and humanly formed in her (divinely, because without the intervention of a man; humanly, because in accordance with the laws of gestation), he is in like manner godless.
Gregory of Nazianzus