"If you really believe God wrote a book, why wouldn't you want to read it?" - Bart Ehrman
A key difference between Catholics and what they call Protestants is our view of the Bible. Whereas Christians rely on the Bible as if it was the word of God (because it is), Catholicism relies very heavily on uninspired, often anti-Biblical tradition, and the authority of the Catholic Church.
For the Christian, the sufficiency of scripture is just common sense. Aside from the fact the Bible explicitly tells us it has everything the man of God needs to be complete (2 Timothy 3:16-17), does it not just make sense that God would be greater than man? Even if you ignore the fact that the Bible says it is sufficient, and just believe maybe God left other revelations in other places, can we at least agree that God's revelations aren't going to contradict each other?
Not so for the Catholic. Most of them have one thing in common: A heavy reliance on (their twisted version of) Church history. Any Biblical case will be met with attempts to justify the doctrine/s in question with Church history. It is especially common for Catholics to claim that it was their Church that produced the Bible, that there were no other Christian groups other than Catholicism until the schism that produced the Orthodox Church, that "Protestant" beliefs were just made up during the Reformation, and that "Protestants" wouldn't know anything about Theology without the help of the Catholic Church.
All of this is demonstrably false, even by the mere existence of the doctrine of Sola Scriptura. Everything "Protestants" have in common with the Catholic Church, we can defend without the aid of the Catholic Church. Every time we disagree with the Catholic Church, we obviously did not get this from the Catholic Church.
In the above image, I have listed three examples of beliefs I, personally, hold, that I rely entirely on the scriptures for. The first is the Trinity. The doctrine of the Trinity is a common belief held by Catholics and "Protestants" alike. No Catholic will ever be able to claim that without the Catholic Church, no one would know about the Trinity. The Bible clearly teaches the doctrine of the Trinity. The Catholic Church neither invented the doctrine, neither do they have any kind of authority to overturn it.
This is the problem with the Catholic reliance on tradition. It assumes the Catholic authority to literally alter doctrine, which most Catholics will admit the Church does not have when it comes to certain doctrines like the Trinity. Imagine, then, how it sounds to a Christian when the Catholic Church erases Biblical doctrines, like the 5 Solas, or adds doctrines, like Purgatory.
The second view I mentioned is Creationism. This is because although I do intend Bible Brain to encompass as many people as possible, my personal area of expertise is Creationism. As a result, this ministry constantly addresses the issue. Although it is possible to defend Creationism with Church history, this is supplementary at best. No one needs to use Church history to prove the correct doctrine of Creation because the Bible sums it up perfectly.
I then addressed my view on Cessationism. This is to really drive the point home. I have my views on Cessationism. However, these beliefs are not based on my study of the scriptures. Rather, I have inherited them from the surrounding culture. As a result, I am not even going to describe what these views are, much less attempt to defend them.
This illustrates that there is some need for the Church. Not the Catholic Church, of course. Your chances of learning good doctrine from them are a lot slimmer than they ought to be. But a Biblical Church is still important. The Church can help inform our views where our studies are limited, as well as keeping each other accountable. However, the Church should always be judged by the scriptures. The scriptures should never be judged by the Church. Where the Church and the Bible disagree, the Bible is correct.
This is a principle that completely invalidates the Catholic Church. The Catholic Church is so unBiblical, it actually knows it. Its insistence on avoiding the scriptures, all while relying on fallible sources, is a tacit admission of its falsehood. As I mentioned earlier, even if you reject the sufficiency of scripture, the infallibility of scripture means God's word supersedes man's. Is it not just logical that the omniscient and omnipotent God, whom Catholics and Christians both acknowledge breathed out the scriptures, will win every dispute with man? How is it, then, that when the scriptures disagree with the Catholic Church, the Catholic Church appeals to man to justify itself? "The scriptures say X". "Oh, but the Council of Trent authoritatively says Y." "The Bible says black". "But this Church Father believed white." "Peter quite clearly taught this." "Well, the Pope is Peter's successor, and he disagrees." What sense is there in this kind of behaviour if you believe God inspired the scriptures? If you follow the Catholic Church, you are following a man-made institution that frequently disagrees with the very word of God. Personally, that's not something I'd want to explain to Him on judgement day.