No one seeing a beautifully elaborated lyre with its harmonious, orderly arrangement, and hearing the lyre's music will fail to form a notion of its craftsman-player, to recur to him in thought though ignorant of him by sight. In this way the creative power, which moves and safeguards its objects, is clear to us, though it be not grasped by the understanding. Anyone who refuses to progress this far in following instinctive proofs must be wanting in judgment. But still, whatever we imagined or figured to ourselves or reason delineated is not the reality of God.
Gregory of NazianzusMore Gregory of Nazianzus quotes
If 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