Why is Mary the Mother of God?
The Bible plainly declares in many passages that the Blessed Virgin Mary is the Mother of God.
The saintly Elizabeth greeted Mary with these words: "
"And behold you shall conceive in your womb, and bear a Son, and you shall call his name Jesus… The Holy Spirit will come upon you, and the power of the Most High will overshadow you; therefore, the Holy Child to be born will be called the Son of God" (Luke 1:31, 35;).
St. Paul says that,
Whence is this to me that the mother of my Lord shall come to me?" (Luke 1:43;)
The Apostles' Creed (circa A.D. 101) professes, "And in Jesus Christ His only Son, who was conceived by the Holy Spirit, born of the Virgin Mary."
"God sent his Son, born of a woman," (Galatians 4:4, cf. Romans 1:3-4).
The belief was so firmly accepted as divinely revealed that the Council of Ephesus (A.D. 431) made it the standard of orthodoxy by proclaiming Mary the Theotokos.