Luke 1 and John 1 do NOT refer to Mary the mother of Jesus as “Mother of God”.
How do you separate Jesus from God? How can you say Jesus is the mother of Jesus without also saying she is the mother of God incarnate, the Word made flesh?
Luke 1 refers to Mary as the virgin who conceived in her womb and gave birth to a son who she is to call Jesus. Luke 1 further says that the holy thing born of her shall be called the Son of God.
How can you say Mary is not the mother of God incarnate without also denying the divinity of Jesus?