Thanks for your questions.
Why do you call Mary mother of God knowing
that God doesn't have a mother?
Because Jesus is God, and Mary is his mother. It's that simple. It doesn't
mean that Mary
pre-existed the Father or the Holy Spirit (or even God, the
Word). It simply means that she gave birth to Christ who was true God and true Man.
The term Mother of God is a marvelous term that concisely
and effectively expresses many essential truths about Christ. It says far
more about Christ than it says about Mary.
For example, if you said Jesus
is God, that's really rather ambiguous.
- Do you mean that Jesus acquired
Godhood sometime during his life, or that he had it from the beginning?
- Do you mean that he was God who appeared to be man, or was he a man somehow
united to God?
All of these questions are made clear when you refer to
Mary the Mother of God, because it implies that Jesus was God from the
beginning, that Jesus was truly man and truly God, and a host of other
things. It's like an entire creed in a single title.
It's the largest three-word, (two in Greek and Latin), Creed in the whole
history of Christendom.
Here is a good article with some additional information on the topic:
- How could Mary be of the tribe of Judah when
we know that she was related to her Levite
I am not sure why you are claiming that Mary was of the tribe of Judah.
Jesus is of the tribe of Judah because Joseph was of the tribe of Judah.
(Matthew 1:3,16; Mark 3:23,33) We don't have a genealogy for Mary.