This is an article written by a Baptist in the February 2007 issue of First Things. Forgive me if it has been discussed already (and post a link, please! I did not find a history of it when I searched myself)
The whole article is found here
Evangelicals and the Mother of God
by Timothy George
Copyright © 2007 First Things (February 2007).
It is time for evangelicals to recover a fully biblical appreciation of the Blessed Virgin Mary and her role in the history of salvation-and to do so precisely as evangelicals. The question, of course, is how to do that. Can the evangelical reengagement with the wider Christian tradition include a place for Mary? Can we, without forsaking any of the evangelical essentials, including the great solas of the Reformation, echo Elizabeth’s acclamation, “Blessed are you among women, and blessed is the fruit of your womb!” (Luke 1:42), or resonate with the Spirit-filled maid of the Magnificat: “My soul magnifies the Lord, and my spirit rejoices in God my Savior, for he has looked on the humble estate of his servant. For behold, from now on, all generations will call me blessed” (Luke 1:46-48)?
So why should evangelicals participate in and celebrate the Marian moment that seems to be upon us? The answer is: Precisely because they are evangelicals, that is, gospel people and Bible people.
Regarding hesitation to address Mary as Mother of God.
There is another dimension of Theotokos, however, that touches evangelical sensibilities. Some forty years ago, Heiko A. Oberman published an important article, using the research of Bishop Paulus Rusch of Innsbruck, in which he argued that the negative Nestorian reaction to Theotokos was initially a response to heretical groups who claimed that Mary was the mother of God not only according to the humanity of Christ but also according to the divinity of Christ, in the same way as there are mothers of gods in pagan religions. Epiphanius of Salamis attested the existence of such heretical groups, one of which he located in Palestine: a community of women who made circular cakes and offered them to the Virgin Mary, whom they had come to look upon as a deity. (This group was called the Collyridians, after the shape of the cakes in their ritual.)