The divine nature is eternal and unchanging, but the Second Person of the Trinity is not identical to the divine nature. The Second Person of the Trinity has *two* natures, joined in a hypostatic union. And the Second Person of the Trinity is God. Therefore, if you had lived in Nazareth 2000 years ago, and pointed at Jesus and said, "Is that God?", the correct answer would be "Yes, that is God." And if you reached out and touched His arm or His foot, you would be touching God. See my post #1676.
-A8
That is correct. However, the Divine nature, that which we call God, is eternal, not subject to birth. Therefore, while one can make a case for technical correctness, the title "Mother of God" is as misleading as calling King David the "Father of God" would be, and for the same reason: In Hebraic thought, which is to say Biblical thought, one's parents and ancestors are automatically in a superior place and in authority over you. It doesn't matter if you're nine or ninety, if your parents, grandparents, etc. live, they are in authority over you, and you are bound by Torah to honor and obey them.
Why do you think the Pharisees had no answer when Yeshua asked them why David called the Messiah "Lord" in Mat. 22:43-45? Because they understood that no father should call his son "lord"--rather, the son should address the father thus. Yeshua was using the Psalm to point out that the Messiah pre-existed His father David as a way of backing up His claim to be One with God.
Now, if we simply spoke of Mary being the Mother of Yeshua, God the Son, in the same way that we speak of the Messiah being David's son, there would be no problem. The problem arises when the Catholic uses the title "Mother of God" as justification for the unBiblical practice of going to her with their requests instead of going to God: "If your mother asked you do do something, wouldn't you do it?"
Yes, but I'm not also my mother's Creator and God. And even so, I would be greatly insulted if my friends, whom I loved dearly and whom I had said to ask me for anything, anytime went instead to my mother to try to get her to pressure me into something instead of coming to me.
Miryam bat Heli is God's daughter, not His mother. She walks in obedience to Him, not He to her. After all, she herself called herself God's handmaiden (Gr. doute, literally, His slave; Luke 1:38)--one is not a slave to one's son.