There is no authority for the church to make it up as they go along ..the church is to teach the gospel not to make up new teachings as they go along by some prophet pope.. ..that is no different than the mormons
She became the Mother of God, in which work so many and such great good things are bestowed on her as pass mans understanding. For on this there follows all honor, all blessedness, and her unique place in the whole of mankind, among which she has no equal, namely, that she had a child by the Father in heaven, and such a Child . . . Hence men have crowded all her glory into a single word, calling her the Mother of God . . . None can say of her nor announce to her greater things, even though he had as many tongues as the earth possesses flowers and blades of grass: the sky, stars; and the sea, grains of sand. It needs to be pondered in the heart what it means to be the Mother of God.
(Commentary on the Magnificat, 1521; in Luthers Works, Pelikan et al, vol. 21, 326)