Theotokos
Mary is rightly called God-bearer because the one she bore is truly God.
This doctrine defines Christian orthodoxy. Denial places one outside the historic faith.
What the traditions say
Dogma. Mary is the Mother of God because the one she bore is a divine person. This follows necessarily from the hypostatic union.
Central to Orthodox devotion. The Theotokos is "more honorable than the Cherubim and more glorious beyond compare than the Seraphim."
Defined at Ephesus (431) against Nestorius. Mary bore the one who is God — this is a Christological claim, not primarily a Marian one.
Luther affirmed Mary as Theotokos and honored her highly. Later Lutheranism maintained the title while reducing Marian devotion.
Calvin affirmed Mary as Theotokos — it's a necessary inference from Christ's deity. But Reformed theology limits Marian devotion to what Scripture explicitly warrants.
Key scriptures
- Gal 4:4 — But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
- Luke 1:35 — And the angel answered and said unto her, The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God.
- Luke 1:43 — And whence is this to me, that the mother of my Lord should come to me?