Jesus existed as God before His human birth.
"I tell you the truth," Jesus answered, "before Abraham was born, I am!" (John 8:58)
Micah 5:2 But thou, Bethlehem Ephratah, though thou be little among the thousands of Judah, yet out of thee shall he come forth unto me that is to be ruler in Israel; whose goings forth have been from of old, from everlasting.
Now, we have clear evidence that Jesus was from eternity. He is the “I am” who has no beginning and no end. Jesus has been God from eternity. He only got His humanity from Mary.
For Mary to be the “mother of God” she would have had to preced Him in eternity which is an impossibility.
You are redefining the term “mother of God.”
That is fine, if you want to divorce yourself from its historical use and introduce confusion.
What would you say if i told you that Catholics (and others who use the term) are not asserting that Mary pre-existed God?
Do you know what we mean by the term? Or are you content to reject it without knowing?