Essentially what Scripture alone boils down to is a question of authority. Who, or what, has the ultimate authority in matters of faith and practice? This was the underlying dispute between the Reformers and the Roman Catholic Church. The Roman Catholic Church holds to a dual source of authority: 1) Scripture and 2) Tradition.
Actually I would say that Sola Scriptura is essentially a question about perception of authority. The Catholic Church freely admits that she has a set core of Doctrines, which we call the Deposit of Faith or Sacred Tradition, by which we interpret Scripture and guide our practices. Most Protestants, except maybe Lutherans and Anglicans, deny the fact that they have a faith tradition of their own, by which they interpret Scripture and guide their practices. The problem is every single Protestant denomination has its on Faith Tradition, it is just denied, because the word "tradition" has been made into a bad word due to Protestant apologetics.
Rome defines tradition as that collection of oral teachings – not recorded in Scripture – which the apostles of our Lord passed down to their successors (the bishops). This oral tradition, because it also claims an apostolic origin, is given equal weight with Scripture; which is merely the written tradition of the apostles. Paul's admonition to the Thessalonian church is often used in support of an apostolic oral tradition (2 Thessalonians 3:6).
This is a false statement. Sacred Tradition is the WHOLE Deposit of Faith, the full Public Revelation. Most of which is found in Scripture, but not all. In all reality even though Sacred Tradition and Sacred Scripture is viewed as separate, Sacred Scripture is part of Sacred Tradition.
One other thing, there really is three sources of authority, not two. The other being the Magisterium, i.e. the body of Bishops. All three sources of authority are needed.
In addition to this dual source of authority, Rome also teaches that the Roman Catholic Church is the sole infallible interpreter of both Scripture and tradition (1 Timothy 3:15). Only the Pope and the Magisterium (the official teaching arm of the Catholic Church) can interpret both Scripture and tradition.
Well you started off right, but the last sentence is questionable. The Magisterium, which the pope is a member of, does not claim sole interpretation of Scripture. Private interpretation is quite acceptable, as long as it does not conflict with the teaching of the faith. In all reality, non-Catholic churches are not much different. Imagine if you will, if you start teaching a works based form of Justification in a Southern Baptist Church. What do you think would happen?
If you really think about, this is no longer a dual source of authority, but a single source of authority – the Church. Scripture and tradition form the source material of divine revelation, but it is the Church that is able to infallibly interpret divine revelation; therefore, authority is invested in the Church alone (or Sola Ecclesia).
Yes you are finally starting to get it. Here is the thing. Jesus Christ didn't leave us a Bible did He? What did He leave us with? A Church.
Now one thing that you may be confused about is what does infallibility mean? Infallibility doesn't mean that whatever you say is true. Actually infallibility is a limitation, not a power. An infallible Church doesn't mean that it can teach whatever it wants and that you have to believe it. No an infallible Church means that it can only teach the truth, no matter how much it wants or not wants to. For example there are many many Catholics, including bishops, who wishes that the Church would change its position on things like abortion, artificial birth control, gay marriage, etc.; yet they keep coming across this big wall that they can't seem to get around so they can make these changes. The wall is, quite frankly, the Church can't, not that it wouldn't, but can't change its teachings concerning these questions.
At one time the majority of Christians, including the Emperor of the Roman Empire, were Arians; and that those who held to the Orthodox faith were the minority. But no matter how many they converted to their view, no matter who was converted, the Arians could not change the teaching of the Church. It couldn't, because of that wall. And now, Arianism in its pure form is no more, except for sects like the JW; and the Catholic Church still teaches the orthodox view of the Trinity. Something to think about.
The Reformers rejected the idea of an infallible Church. They recognized that even the best of men could make mistakes. Only the word of God is declared to be divinely inspired (2 Timothy 3:16). As divinely inspired, only the Scriptures can rightly said to be infallible. Therefore, the Reformers broke away from the Catholic Church by declaring Scripture alone to be the only, infallible rule of faith and practice.
Well a couple of things. The Rebels had to reject the infallible Church. If they didn't it would be kind of hard to rebel wouldn't it? How many people could they have swayed to their side if their selling point was "hey the Church is infallible, but we are going to go against it anyway, so who is with us!" I think the Protestant Rebellion would have ended much differently. So their problem fell to what can we claim as ultimate authority? Well the teaching of Bible was the only thing that could be manipulated to say whatever they wanted. So that made perfect sense.
The point being is simple, there is no such thing as a Sola Scriptura church. It doesn't exist. Why? Because everyone reads Scripture through the lens of their faith tradition, or someone else's faith tradition. The only way I could buy the idea of Sola Scriptura is that if every church that taught this as doctrine, had at the end of the day, the exact same set of core beliefs. Maybe practices were different, some outlying doctrines; but the exact same set of core beliefs.
You know what I find interesting is that there is this thing called the "5 Solas" right? That every Protestant is suppose to believe, which would provide the core beliefs. The problem is, that Protestants can't even agree on what these five Solas actually mean. Sola Scriptura is nice in theory; but in practical terms falls flat on its face.