If you're ever doubting which doctrines come from God, pay attention to how heavily they rely on His word. When it comes to Catholicism, the answer is not very heavily at all. While they claim theirs is the one true Church established by Christ Himself, they put remarkably little emphasis on the Bible, even trying to claim authority over it, whereas they will make silly claims like "to be deep in history is to cease to be Protestant". That's not to say they don't give lip service to the Bible, or even that they never cite it, but their primary argument is history.
The main problem with arguing from history is that history, by definition, is descriptive, not prescriptive. History is about what happened in the past, but it cannot comment on whether or not that should have happened. Throughout history, many great evils have occurred. History, even as it is described in Holy writ, is replete with examples of men doing what they ought not do. Of course, it is also filled with examples of men doing what they should have done. The question is, how do you know the difference? By God's word, of course! We can see that God's chosen people worshipped the Queen of Heaven, but just because they did doesn't mean we should worship the Queen of Heaven. God's word says they provoked Him to anger by doing that, so it happened, but it shouldn't have.
Just as history is replete with evil deeds, so also is it replete with evil thoughts. We can show, for example, that Augustine of Hippo was, at some point in his life, a filthy misogynist who claimed women would be useless apart from childbearing. Note, first of all, that just because Augustine wrote this does not mean it is representative of the views of the entire Church, neither at his time, nor up until then. Catholics love to cite Church "Fathers" who appear to agree with them in that particular quote, as if this settles all things. If you can show a Church "Father", or two, or several, who held a particular view, this is said to be proof that Catholic tradition was always the understanding of the Church. But given that even in the New Testament, we see endless divisions, even in the name of individual Apostles, do we seriously imagine that the existence of one view precludes the existence of another?
This reasoning is especially absurd given the fact the Church "Fathers" very often do disagree with each other, and even with themselves. Augustine alone did not hold the same views throughout his faith. He even wrote an entire work called "The Retractions", in which he surveys his older works and explains how his theology has changed. It's worth noting that this includes his previous teaching that Peter was the rock upon which Christ built His Church. This doesn't fit very well with First Vatican Council's claim that the Church has always understood Peter to be the rock upon which the Church is built.
And this illustrates a far bigger problem with history; there never was a long and constant string of tradition. When Catholics boast about their 1500 years of tradition, as if the Reformation invented brand new doctrines and no one doubted the Catholic Church until then, they forget (or just don't know) that actually, the Catholic Church of today is not the same as the Catholic Church of the 1500s, the 1200s, the 1000s, the 500s, or even the 300s.
One of the most noteworthy examples is the so-called Great Eucharistic Controversy. One could hardly imagine two Catholics debating the Real Presence today, but prior to Fourth Lateran Council in 1215 A.D., this was not an official Catholic doctrine. That's not to say no Catholic believed in the Real Presence. Indeed, Paschasius Radbertus, author of "De corpore et sanguine Christi" (Concerning Christ's Body and Blood), argued for just that in 831 A.D. Yet, one of his many opponents was a fellow monk by the name of Ratramnus, who believed a concept more similar to Luther's Consubstantiation.
The above basically means that, far from teaching consistently for 1500 years before Luther, the Catholic Church did not even officially adopt what is now one of its core doctrines until halfway through its history. In other words, Catholicism is subject to change. Indeed, John Henry Newman, to whom the aforementioned "deep in history" quote is attributed, wrote an entire essay in which he describes his theory of the Development of Doctrine. That is, his excuse for why the Catholic Church always seems to be making stuff up, but in reality, he says, it was always there, it just wasn't as explicit.
Compare this to scripture. Does scripture tell us to expect more doctrines/dogmas in the future? Does it even permit us to add to it? Absolutely not. Jude tells us that the faith was delivered once for all to the saints (Jude 1:3), and throughout scripture, even as a point of Mosaic law (Deuteronomy 4:2), changing God's law through addition or omission is shown to be a very bad thing. Why, then, should we heed the many additions the Catholic Church has added?
But the Catholic might object and point out that things have been added to scripture since Deuteronomy. But I can tell you exactly why we should heed those particular additions: We can't add to God's word, but He can. See, both Christians and Catholics acknowledge the theory that scripture is divinely inspired. God didn't promise He would never add anything, He forbids us from adding anything in His name.
According to Peter, "...no prophecy of Scripture is of any private interpretation, for prophecy never came by the will of man, but holy men of God spoke as they were moved by the Holy Spirit." (2 Peter 1:20-21). The prophets and Apostles were not making things up as they went along. Rather, they spoke what God told them to speak. Can the same be said for history? With the obvious exception of the history recorded in scripture, the answer is certainly not. We find mutually exclusive accounts, missing details (and strange attempts to fill them in), dubious stories, odd chains of transmission, and so much more.
As an example, take the so-called Miracle of Lanciano. This supposedly took place in the early 700s A.D., yet the oldest known record of it comes from 1636! That's 900 years after the event itself. Usually, in Christianity, when evidence for an event is that shaky, we throw it out. Pseudepigraphal gospels have stronger evidence than that. The Gospel is certainly stronger; all of the New Testament was written within the same century, even within living memory, as most of the events it describes (though there is evidence Christ may have been born as early as 4 B.C.). In other words, even if it was just human beings writing the Bible without God's direct inspiration, it would still be the absolute best authority on the Christian faith and the beliefs of the early Church.
Better still is its preservation. A natural drawback of history is decay. Evidence dissolves. People and events are forgotten. In some cases, whole cultures disappear without a trace. But God has promised to preserve His word, a promise He has fulfilled quite spectacularly. Satan could throw the biggest tantrum in history, God's word would still be available to mankind in some form or another. We have, by contrast, lost a lot of knowledge about the early Church. Heck, the Catholic Church itself is notorious for burning things they didn't like, even to the point of killing people they considered heretical.
So with all this in mind, why do Catholics so swiftly run from scripture to history? For one simple reason: They would rather be in the company of men than of God. Much like the Pharisees before them, the Catholic Church values man made traditions, drawing near to God with their lips, even acknowledging the scriptures, but ultimately rejecting Him by conflicting with them. Any Church that cries "history" in response to "it is written" loses the right to claim they were established by the God it is written by.