Today is the Solemnity of Mary, the Holy Mother of God. Mass readings are here. If you're a Catholic, today is a holy day of obligation. Get thee to church!
Why is it so important that Mary is the Mother of God? I think we often take this title for granted - of course one would call her the Mother of God! It has apparently not always been so obvious though. From the ever reliable Wikipedia:
The Council of Ephesus was a council of Christian bishops convened in Ephesus (near present-day Selçuk in Turkey) in AD 431 by the Roman Emperor Theodosius II. This third ecumenical council, an effort to attain consensus in the church through an assembly representing all of Christendom, confirmed the original Nicene Creed, and condemned the teachings of Nestorius, Patriarch of Constantinople that Virgin Mary may be called the Christotokos, "Birth Giver of Christ" but not the Theotokos, "Birth Giver of God". It met in June and July 431 at the Church of Mary in Ephesus in Anatolia.
Nestorius did not hold that Jesus Christ was one in His divinity and humanity. If this was true, Mary would have only brought forth Jesus the man and not Jesus as God, and Mary would not
be known as the Mother of God but as the Mother of Christ. The argument about Mary's title was actually more about the nature of Jesus then it was about Mary herself. In calling Mary "the Mother of God," we are affirming Christ's true nature as both entirely human and entirely divine.
The more I study the faith, the more and more I find this to be the case. Whatever we say about Mary is more about Jesus than it is about Mary herself. The Rosary is probably the most popular prayer / meditation among Catholics, and we are often accused of worshipping Mary as a result. If we look at the parts of the Rosary though, we find it is all about Jesus. All of the mysteries we meditate on are about Jesus, even the two that are more explicitly about Mary (Assumption and Coronation) as they only come about because of God's saving power, plan, and grace. Proper devotion to Mary always points to Jesus.