Nestorious should be ashamed, and should place his hand on his lips. This Child is God. How then can she who bore Him be anything but God's Mother? If anyone does not acknowledge her as Mother of God, such a one is far removed from the Godhead. These words, though it is I who use them, are not my own for I have inherited these glorious teachings from Gregory the Theologian.
Let us adore God alone, the Creator and Maker of all things. Let us offer to Him the worship of latria as to God who is of His very nature adorable. Let us revere, too, the Holy Mother of God, not indeed as God, but as God's Mother according to the flesh.
Saint John Damascene (676-754)
Further reading
The passage connects Mary’s title to faith in her Son and distinguishes devotion from divine worship. Scott Hahn’s Hail, Holy Queen follows Marian teaching through Scripture, providing a readable biblical companion to those two concerns.
Hail, Holy Queen: The Mother of God in the Word of God by Scott Hahn (paperback) on Amazon (paid link)