Where does the Bible say that? Since Jesus is God, how can Mary--"the mother of Jesus"--not be the Mother of God?
The Lord Jesus was the only begotten of the Father, before the foundation of the world, as He created all things.
In the beginning was the Word, and the Word was with God, and the Word was God. 2 He was in the beginning with God. 3 All things were made through Him, and without Him nothing was made that was made... and the Word became flesh and dwelt among us, and we beheld His glory, the glory as of the only begotten of the Father, full of grace and truth.
John 1:1-3,14
The Word became flesh.
He became, or was made a little lower than the angels.
But we see Jesus,
who was made a little lower than the angels, for the suffering of death crowned with glory and honor, that He, by the grace of God, might taste death for everyone.
Hebrews 2:9
Mary gave birth to the flesh and blood man, named Jesus Christ.
The Son of God
[God the Son] had His existence and was begotten of the Father, long before Mary was born or before the foundation of the world.
He is the image of the invisible God,
the firstborn over all creation. Colossians 1:15
The Son of God created all things.
16 For by Him all things were created that are in heaven and that are on earth, visible and invisible, whether thrones or dominions or principalities or powers. All things were created through Him and for Him. 17 And He is before all things, and in Him all things consist.
Colossians 1:16-17
He, The Lord Jesus, as God, created Adam from the dust of the ground and breathed the Spirit of Life into Him.
And the Lord God formed man
of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living being.
Genesis 2:7
Mary came from Adam.
The Body that was prepared for Him, came from Mary's womb.
Therefore, when He came into the world, He said:
“Sacrifice and offering You did not desire,
But a body You have prepared for Me.
6 In burnt offerings and
sacrifices for sin
You had no pleasure.
7 Then I said, ‘Behold, I have come—
In the volume of the book it is written of Me—
To do Your will, O God.’”
Hebrews 10:5-7
Mary gave birth to the flesh and blood body that all the fullness of the Godhead dwelt in.
Mary did not
give birth to God.
Hopefully you can rightly divide the Word of truth here and see that Mary gave birth to the Man Jesus Christ, who died on the cross for our sins.
15 But the free gift
is not like the offense. For if by the one man’s offense many died, much more the grace of God and the gift
by the grace of the one Man, Jesus Christ, abounded to many.
Romans 5:15
JLB