Catholics refer to the Blessed Virgin as Holy Mary, Mother of God. Since we are all called to be holy, the first part of this expression is rarely challenged. However, those who reason that in order for Mary to be the mother of God she would have to be God often question the second part. What this shows is a total misunderstanding of the intent for which this title was bestowed. A look at both the practical and historical use of it can offer some explanation.
Practically speaking, every one of us is a composite being of body and soul. The women that conceived and bore us gave life to our physical being. God alone created our soul. Yet these women are still regarded as the source of our entire being and we rightfully call them our mothers. Similarly, the Blessed Virgin conceived and bore Jesus, giving Him physical being and human nature. Although He possesses divine nature as well, Mary is still His mother. Since Jesus is one in being with the Father, it is entirely proper to refer to Mary as the mother of God. In Luke 1:43, we are told that Elizabeth called Mary “the mother of my Lord” while under the inspiration of the Holy Spirit. When we call Mary the mother of God, we follow this example.
Historically speaking, the title “Mother of God” (in Greek “Theotokos”) was bestowed on Mary at the Council of Ephesus in 431 A.D. to emphasize both the human and divine natures of Jesus in one person. In referencing this Council, the Catechism (par. 495) indicates, “ . . . the one whom she conceived as man by the Holy Spirit, who truly became her Son according to the flesh, was none other than the Father’s eternal Son, the second person of the Holy Trinity.” Thus each time we pray the Hail Mary we acknowledge the two natures of Jesus in one person along with Mary’s special role in making this happen.
Learning and understanding the reasons for our beliefs confirms our confidence that the Catholic Church possesses and continues to faithfully teach the fullness of the inspired truth of God’s Word. Don’t settle for anything less.