I urge you to read a book on the development of doctrine in early Christian history. You will find that those declared as heretics used the very same Scriptures to prove their points of view as being correct, much as you do today. Even in the Second Century, Catholics were writing about Gnostics who were "appropriating" the Scriptures to suit their fanciful theories. Today, we see this with the Jehovah Witnesses and the Mormons - who aren't Christian. If Scripture was so obvious and could only be taken one way, why do people of good will completely disagree on so much of it?
Regards
As Jo explained to you, the Scripture is not self-explanatory, or we would not have heretics of any description running around. At the same time, no, the Church does not have a monopoly on understandig the Scripture, as many Protestants and unbelievers convert to Catohlicism and Orthodoxy having convicted themselves of the truth of the Church through independent study. Some come home after they had enough of their Protestant pastors. Tim Staples even wrote a book once, "Jimmy Swaggart Made Me Catholic".