Because *mother of GOD* says something different than *mother of Jesus*.
If you told someone who had never heard the gospel before that Mary was the mother of God, how could they automatically conclude, *Oh, you mean Jesus*?
Proper teaching on who Jesus is does away with the need to rename Mary, which only leads to more error and on to worship of her, as is admitted in the title of this thread.
Proper teaching of Jesus uses..... ***SCRIPTURE***
It doesn’t happen with more error.
I didn’t ask what Mary was. After reading what John Calvin said, I now understand why some would be uncomfortable with the expression *mother of God*.
Do you believe that the son of Mary is God? And as such, Mary can be called the mother of Jesus, who is God in the second person of the Trinity?