Most Protestants recoil from the idea that they should let a group of (mere) men interpret God’s Word for them and tell them what to do and believe. We all have experience with the incompetence of large groups of people, and the idea that a huge bureaucracy can make any kind of good decision on anything, much less matters of eternal significance, seems preposterous. So Protestants rely on the Bible and their own brain to tell them what the truth is, and believe that they are trusting no one less than God himself.
The first problem is that God’s Word has always been transmitted through man. Yes, there have been times when God has revealed himself directly to an individual (fun fact! The Catholic Church calls the appearances of saints, etc, to random people “private revelations,” and they don’t require that any other individual necessarily believe in them, hence the term “private.”), but for the most part he has spoken through prophets and other men to deliver his messages to people in general. In the Old Testament, Moses went up on the mountain to tête-à-tête with God, and came down with the law: the people had to trust that God was working through Moses. Throughout the history of Israel, God sent prophets to tell the people what he wanted: they had to trust the prophet (that doesn’t mean blind acceptance; there are standards for what you believe God has revealed. I’m talking to you, Scientologists). Jesus came and spoke directly as God, but when he returned to heaven he enabled his disciples to spread what he had said throughout the entire world, and the people had to trust that what the apostles said about God was true. Before the books of the New Testament were written, the apostles preached and taught throughout the known world, only writing down some of what they said. By the time the New Testament was canonized, the Church was already formed, preserving and passing down what the apostles had taught.
The second problem is that the Bible is not easy to understand. The Jewish Scripture had always been held in a framework of tradition passed down through the generations, and the same has held for the Christian Bible. The immensity and complexity of the collection of books guarantees that even if someone has the knowledge of history, language and theology to truly understand everything in it, he wouldn’t have enough time in his lifetime to unpack it all. Right now, after two thousand years, the Catholic Church still doesn’t claim to know the exact meaning of every passage of Scripture, and they’ve had some of the best minds in western civilization working on it. The understanding that the Church has of Scripture has continued to develop over the centuries; although the Church maintains that revelation ceased with the death of the last apostle (something that most Protestants believe, too), she believes that our understanding of God’s Word continues to grow and become more detailed. What God has revealed is neither so simple that every person can comprehend it upon a quick glance, nor so complicated that only a few can understand it.
The third problem, which I think is more a misunderstanding, is that the Catholic Church doesn’t define “infallibility” as always being perfectly right about absolutely everything, every time. Infallibility just means that the Holy Spirit will prevent the Church from making an absolute teaching about faith or morals that is incorrect. For a former Protestant, it’s easiest to understand it like how the Holy Spirit worked through the apostles preaching God’s Word in the early years of the Church. The leaders of the Church taught the truth, but that didn’t mean that they didn’t sin in their own lives, or that they spent every moment just spewing the direct voice of God out of their mouths. When issues came up about correct doctrine or morals, they got together and hashed it out and decided what the truth was. (See Acts 15. Aside, it is fascinating to read Acts and the other New Testament books in the context of the Church as a living, visible entity, not just a word used to refer to Christians in the collective sense.) One thing that they didn’t do, incidentally, was just let anyone go around preaching conflicting teaching and say, “Well, he understands it differently.” They actually got pretty heated when people started teaching things that didn’t agree with the teaching of the apostles.
The fourth problem with denying the role of the Church in interpreting the Word of God is that Protestants do the exact same thing. If all Scripture was clear and the Holy Spirit taught everything to each individual, there would be no seminaries, there would be no Bible colleges, or pastors, or sermons, or books about the Bible or Christian teaching or radio programs explaining the Bible or TV shows or magazine or any of the multitudinous resources that Protestants use in their attempts to understand the Scripture. If the Protestant understanding is correct, every Christian would have to be fluent in Biblical Hebrew and Greek in order to understand the original manuscripts, as well as being intimately familiar with every social, cultural and rhetorical device used in the books. A translated work would be useless, because the translator could have misinterpreted something. It just doesn’t make sense that the Word of God would be limited to a set of static words in unfamiliar languages.
This makes much more sense to me than the Protestant understanding; to be a Protestant is to never really know, even in your own heart, if you believe the right thing. For all you know, in a few years you could hear a new interpretation of something and suddenly realize that you had been wrong up to that point. I often felt inadequate as a Christian when I was a Protestant because I couldn’t make everything in the Bible make sense, and I had no way of reconciling differing viewpoints. Not to mention the tension when fellow believers interpreted things differently. For every Protestant teaching backed up by Scripture, there is an opposing view backed up by Scripture. It doesn’t make sense that God deliberately left his people in chaos.