If God was magnified by the Soul of just one human being, and the Gospels tells us that was the case, how could a sin disordered soul magnify perfection?
How does Mary being sinless detract one jot or tittle from your conception of the faith? Contrariwise, why must you insist that the Mother of God was sinfilled to sustain your faith? Even the arch-heresiarch himself, Martin Luther, acknowledged Mary as sinless and a perpetual Virgin.
I would suggest that God is not magnified by us. He is magnified through us.
Scripture teaches that we can do nothing good of ourselves. God bring glory to Himself by working through us. We emulate His light. As Mary acknowledges, "For he hath regarded the low estate of his handmaiden: for, behold, from henceforth all generations shall call me blessed." God was not magnified by Mary. Rather God was magnified through using Mary. God was glorified. Yet Mary was blessed because people can look back on her as an example of God chosing a person to use.
... how could a sin disordered soul magnify perfection
How can a donkey talk? How can an iron ax float? How can the Red Sea part? God works in ways we cannot understand. The virgin birth was necessary in order for Christ to be stainless from the sins of Adam. This does not mean that Christ could not be surrounded by a sinful world. In fact He was.
...why must you insist that the Mother of God was sinfilled to sustain your faith?
I don't need to insist that Mary was sinful and I certainly don't need it to sustain my faith. The scriptures plainly states that "All have sinned and fall short of the glory of God." Mary states that "...my spirit hath rejoiced in God my Saviour." And we are told that "All we like sheep have gone astray and the Lord has laid on Him the iniquity of us all." If Mary is a sheep of God, then she went astray from time to time. It's just what the infallible word of God states. So I can either believe what I read in the unerring word of God or I can believe what sin filled people tell me.
If one will recall the story of Enoch in scripture, here was a person who lived such a wonderful life that the scriptures tells us that God took him. Enoch never saw death. Yet clearly the Church doesn't elevate Enoch to the same level as Mary.
The beauty of Mary is not that God kept her from a sin filled life. Rather the beauty of Mary is that God used her in spite of her fallen nature. He understands our falleness and helps us to understand our fallen nature, so that we might depend on Him to overcome this brokenness.
Even the arch-heresiarch himself, Martin Luther, acknowledged Mary as sinless and a perpetual Virgin.
I'm sure you would acknowledge Martin Luther was wrong on occasions. If he stated this, why would you believe this to be correct?