"When the immaculate conception was first presented in the year 1140 it was opposed by Bernard of Clairvaux also Thomas Aquinas adamantly taught Mary was a sinner"
I think you are mistaken. Both of these great saints were very devoted to Mary. The concern that they both had regarding the Immaculate Conception was that they had thought that if the Church said Mary was immaculately conceived, it would imply that Mary did not need God's salvation to save her from original sin. Some Protestants continue to make this argument.
However, Scotus would solve this problem a little later. He basically said that Mary was saved, except in a different way, from other men. Mary was saved from ever contracting original sin. In other words, God prepared Mary before her birth. The fact that Augustine, the formulator of the doctrine of original sin, went out and explicitly said "of course, the virgin Mary, I exclude from such matters," says a lot of the sense of the faithful that Mary was immaculate, way before the dogma of the Immaculate Conception was defined as dogma. The Church has always considered Mary to be the New Testament's version of the Ark of the Covenant - the "container" for the Word of God, the High Priest, and the Bread of Life - Jesus Christ. This "container" was pure in both Testaments.
Regards
***However, Scotus would solve this problem a little later.***
I must say this seems like speculation on his part without Scriptural support.
***He basically said that Mary was saved, except in a different way, from other men.****
And how exactly would he come to know this 1250 odd years after the fact? Is it present in the Scriptures? Was it revealed to him by Heaven?
***The Church has always considered Mary to be the New Testament's version of the Ark of the Covenant ***
You know, the funny thing is that it is Jesus to whom the ark point and whom it symbolizes.
"The acacia wood symbolized the Lord's humanity. The gold overlay denoted His deity. The Law inside the Ark pictured Jesus with the Law of God in His heart, living in perfect obedience to it. The pot of manna spoke of Jesus as the Bread of Life or our life sustainer. Aaron's rod that budded obviously prophesied the resurrection.
The mercy seat was also a symbol that pointed to the Messiah. It was representative of the fact that the work of Jesus on the Cross would cover the Law of God with His mercy. It is an illustration of how the divine throne was transformed from a throne of judgment into a throne of grace by the atoning blood that was sprinkled on it."
Really the whole tabernacle symbolizes Jesus. It's quite an amazing study.