What is the right time [to discuss theology]? Whenever we are free from the mire and noise without, and our commanding faculty is not confused by illusory, wandering images, leading us, as it were, to mix fine script with ugly scrawling, or sweet-smelling scent with slime. We need actually 'to be still' (Ps. 46:10) in order to know God, and when we receive the opportunity, 'to judge uprightly' (Ps. 75:2) in theology.
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