Peter gets what I always thought was a raw deal. Christ calls him Satan simply because Peter seemed to care about His well being in trying to save Him from his future crucifixion (Mark 8:27-33). But it is all clarified in Christ's statement, "You are thinking not as God does, but as human beings do." In other words, you are missing out on the big picture Peter. Instead of preserving Christ's mission you looked to preserve Christ and, oddly enough, to preserve Christ the way in which you want Him would be to lose Him.
So it is with the Church. An excellent discussion on The Curt Jester (Why Do We Need These Solutions Now) looks at those who say that the Church must be preserved at all costs. All that needs to be done, say some, is to get in line with the prevailing culture (read: married and women clergy, abandoning teaching on pre-marital sex, divorce and marriage, abortion, contraception and the usual host of other issues.) Yet our goal should not be to preserve the Church. The faith is not here to preserve the Church, the Church is here to preserve the faith. If we corrupt the faith to preserve the Church, we lose the need and meaning of the Catholic Church. Yet, if we preserve the faith, the Church will survive. It may not be in the way that we want it, but keeping it the way we want it is thinking like human beings do. We need to think like God does and that means preserving the faith which He gave us above all things.