My brethren, I'm afraid I have a very sad announcement. The Apostles, who lived nearly 2,000 years ago, are dead. I know, it's going to take a moment for you to process this tragic news, and I'm sorry to have to be the one to tell you, but that's just the way life works.
Of course, I don't actually need to tell you this. Most people barely make it past 70, so it should be obvious that the Apostles didn't last 21 centuries. However, Catholic apologists assure me that 2 Thessalonians 2:15 requires Christians to listen to their oral teachings, too. And of course, those oral teachings are conveniently where we'll find the majority of Catholic doctrine.
Now, 2 Thessalonians 2:15 is helpful enough to clarify which traditions it is talking about. It is the traditions the brethren were taught either by the Apostles' word, or the Apostles' epistles. As I said, the Apostles are now, in fact, dead. Therefore, we no longer have to listen to the words of their mouths, because they are no longer capable of using their mouths to speak. The only relevant source of tradition mentioned in 2 Thessalonians 2:15, therefore, is the epistles.
This is where Catholic apologetics starts to get convoluted. Catholics not only reject the sufficiency of scripture, but also reject the perspicuity thereof. That is, they deny that A. the scriptures are enough and B. you are capable of interpreting it correctly without their help. Therefore, not only do they get to tell you what the traditions in the Apostolic epistles mean, but they also get to add traditions to the faith.
This reasoning is more circular than the letter O. In order to "prove" their authority, Catholics must assume it in the first place. This can be seen in their use of scripture in apologetics, 2 Thessalonians 2:15 being an excellent example. The only real way to find Catholicism in the Bible is to have prior exposure to the Catholic Church. You need their "help" to find their faith. When a Catholic brings up 2 Thessalonians 2:15, you have every right to reject their interpretation, and to give the very explanation I am giving now. But a Catholic will claim you're only reading it "wrong" because you don't accept their authority. They are using this verse to prove their authority, but using their alleged authority to interpret this verse. This effectively amounts to "the Catholic Church is true because the Catholic Church says the Bible says the Catholic Church is true".
But is it possible that the Apostles said more by mouth than they wrote down in scripture? First, yes, of course it is. The Apostles were as unique as they were Apostolic. Peter was a fisherman, so probably taught people how to fish. Maybe he even used fishing analogies to teach his flock apologetics tactics. Paul was a Pharisee, exceedingly zealous for the traditions of the Pharisees. Not all traditions are bad, such as washing hands before you eat (Matthew 15:2; Mark 7:3). Could Paul have continued washing his hands before he ate? I don't see why not.
But one thing we can be absolutely sure of is that while the Apostles may have preached more than they wrote down, they certainly didn't contradict what they wrote down. First, this is just common sense, isn't it? Sure, there were times when the Apostles played the hypocrite (Galatians 2:11-13). They were still sinners, after all. It's not like they received the Holy Spirit and boom, suddenly there were 12 more Jesuses walking around. But surely Catholics would agree that we ought not imitate the Apostles' sins? When Peter played the hypocrite, Paul didn't tell the Thessalonians "therefore, you should copy the tradition of Peter and compel gentiles to live as Jews". No, he flat out resisted Peter to his face.
So obviously, that wouldn't be good. If the Apostles ever preached more sinful things, we can be glad those sins are forgotten. We certainly don't need to pick them up and repeat them, nor is it logical to assume they would want us to. But furthermore, it is common sense, because Christianity isn't a made up religion. The leaders of made up religions can be as hypocritical as they want. It makes sense for Muhammad to preach that Muslims are "only" allowed 4 wives at one time, yet for him to take up to 11 for himself. Muhammad was a liar. But were the Apostles liars? Far from it! As Peter points out in 2 Peter 1:16, "For we did not follow cunningly devised fables when we made known to you the power and coming of our Lord Jesus Christ, but were eyewitnesses of His majesty." Now, if you want to argue that Christianity is just another man made religion, and therefore it does make sense that the Apostles would teach contradictory things, go nuts, but I'm not sure why you'd want to be a Catholic if the only way you can defend it is by claiming the Apostles made it up.
It makes sense, then, that the Apostles didn't teach contradictory things. Neither did they even believe they had the authority to do so. Furthermore, they taught that it was wrong to think of men, including themselves, beyond what is written (1 Corinthians 4:6). In other words, if something isn't written down about men, no one under the authority of the Apostles (or at least who believes Paul held authority) can consistently think it. This already shoots Catholics in the foot, as their religion requires them to think of many men beyond what is written. For example, where is the primacy of Peter in the Bible? The Bible contains nothing like the Papacy, and indeed, the Peter of the Bible was anything but papal.
As for the Church's view of the Apostles, the Apostles viewed themselves as "stewards" of the mysteries of God (1 Corinthians 4:1). A mere steward will always be less authoritative than the message he brings. Again, it makes perfect sense for inventors of a false religion to change their message willy nilly, but if the Apostles were only stewards of the truth, they have no authority to change the message. Not even slightly. In fact, Paul explicitly says so. In Galatians 1:8-9, he writes "But even if we, or an angel from heaven, preach any other gospel to you than what we have preached to you, let him be accursed. As we have said before, so now I say again, if anyone preaches any other gospel to you than what you have received, let him be accursed."
This statement carries a lot of weight. First, note how it says "as we have said before, so now I say again". This is significant. It shows that, as preachers still do today, the Apostles preached the same message in both written and spoken format. If you want to know what the Apostles said, read what the Apostles wrote. As this article has hammered to death, it will be the same consistent message, not a contradictory mess.
Second, Paul clearly submits both himself and the other Apostles to God here. Paul effectively told the Galatians "if I come back and start preaching something different, you judge me by what I've written now". The same with the other Apostles. Even the same with an angel. An angel from Heaven, no less. The message carries so much authority that the only one with any authority to change it happens to be the same God who, by His very nature, will not do so.
Third, this specifically refers to the Gospel. Note how Paul doesn't just say "if anyone brings a contrary Gospel". No, he simply says any other Gospel. If someone says you can as easily be saved by perfecting a complex yoga technique as if you confess Jesus as Lord and believe in your heart God raised Him from the dead, they're covered by this.
This is absolutely what the Catholic Church has done. The so-called gospel of Catholicism is convoluted, hopeless, and contradictory. On the one hand, it is claimed that grace is handed out piecemeal. A Catholic believes he receives grace through the 7 sacraments. Furthermore, there are two categories of sin: Mortal and venial. If they die without having a venial sin resolved, they spend time in Purgatory. If they die without having a mortal sin resolved, they go to Hell. What's terrifying is the ambiguous definition of "mortal sin". A mortal sin is a conscious and deliberate sin. If you know you're sinning, yet do it anyway, that's mortal. In other words, if you see someone drop a 20p and you know you should give it back to them, but instead pick it up and pocket it, you better hope you can get to your priest in time for him to absolve you, because otherwise, you're off to Hell. The cross is not enough.
Oh, but it gets worse, because on the other hand, while a faithful Catholic can commit a mortal sin and go to Hell, it's possible to go to Heaven without even knowing the Gospel! According to the Catechism of the Catholic Church 847, "Those who, through no fault of their own, do not know the Gospel of Christ or his Church, but who nevertheless seek God with a sincere heart, and, moved by grace, try in their actions to do his will as they know it through the dictates of their conscience - those too may achieve eternal salvation." Contrast that with the fact that the Bible bangs like a beating drum that literally the only way to be saved is through Christ. The concept of those who have not heard is even addressed in Romans 10:14-17. The long and short of it is that they can't really seek God, sincerely or otherwise, if they don't know Him. And of course, without faith, it is impossible to please God (Hebrews 11:6).
So we see that the "gospel" of the Catholic Church is very much different from the Gospel the Apostles preached. But it's ok, because of Apostolic succession, right? Well, first off, as we've already shown, the Apostles didn't have the authority to alter the Gospel either. In fact, they would be declared anathema if they did, and Paul would have specifically encouraged the Galatians to reject them. So already the Catholic Church must claim to have more authority than the Apostles and the Heavenly host. But consider also Paul's words to Timothy: "As I urged you when I went into Macedonia—remain in Ephesus that you may charge some that they teach no other doctrine, nor give heed to fables and endless genealogies, which cause disputes rather than godly edification which is in faith."
So first we see, once again, that preaching other doctrines is out of the question (not to mention that this verse once again shows the Apostles' written teachings were identical to their oral teachings). Paul isn't going to write "teach no other doctrine" and follow it up in person with "oh yeah, here's this other doctrine". But second, it says not to give heed to fables, which the Catholic Church does frequently, nor endless genealogies, which is similar to the claim of Apostolic succession.
Now, to be fair, there is a difference between a genealogy and a succession. Genealogies are bloodlines. Sort of like the Jews did to boast in themselves over other Jews. Nevertheless, the same principle can be applied. What matters isn't succession. If the message supersedes the messenger, what matters is commitment to the message. If it could be shown that there has always been an unbroken line of Popes from Francis back to Peter, this would not matter if Francis is not preaching what Peter preached.
Furthermore, it is demonstrably false. There are many breaks in the Papal line, because there have been multiple times in history where numerous people have had "legitimate" claim to be Pope. The Great Western Schism is an excellent example. 3 rival Popes held office, each declaring the others to be imposters, and excommunicating them. This was only ended by the Council of Constance (1414 - 1418), which forced all three contenders to step down and elected Pope Martin V instead. This is a rather significant break in the Papal line, is it not? That's ignoring the absence of evidence Peter was a Pope, the evidence that he certainly wasn't, and the fact that there were no Popes for at least 300 years (just like with Peter, the Catholic Church retroactively projects the role of Pope onto people who simply were not Papal).
But does any of this really matter? We spend so much time babbling about the Apostles and their alleged successors, but Catholics need to remember that in the end, Christianity isn't about the Apostles, it's about God. And Catholics have to admit that the Bible is the word of God. In the Dogmatic Constitution on Divine Revelation, Dei Verbum, Pope Paul VI explicitly teaches that the Bible is the word of God, and by that token, is to be "venerated" with equal loyalty and reverence to "sacred" tradition.
The Bible agrees with the first half of this statement, but what about the second half? In 2 Timothy 3:16-17, we read "All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work."
This verse shatters the whole argument about what the Apostles may have taught that they didn't write. First, it says that scripture is useful for doctrine, reproof, correction and instruction in righteousness. Already we have a clear cut statement about how a Christian can use the Bible as a source for all of the above. In other words, no Church necessary. I can use the Bible in the same way as I use an instruction manual for operating a machine, or building a piece of furniture. It really shouldn't be too difficult. By contrast, the Catholic Church claims that the Bible belongs exclusively to the Catholic Church, and at one point, expressly banned the common folk from possessing it. This is why they strangled, burned, and exploded William Tyndale. Whereas a Catholic Bishop said it is better to be without God's laws than the Pope's, William Tyndale wanted a plow boy to be able to read the. Bible, so he set out to translate it illegally. The KJV draws very heavily on Tyndale's work.
But "more important", for lack of better term, is verse 17. Catholic apologists hate this verse. In fact, it has been my experience that, no matter how hard you press, they generally don't address it. You can emphasise it, circle it, underline it, put the words "complete" and "thoroughly" and "every" in capital letters, most Catholics just want to focus on verse 16. "We believe it's inspired, too". Yes, but you do not believe it makes the man of God complete, or thoroughly equipped for every good work. The argument is not now, nor has it ever been, "the Bible is inspired by God, therefore it is the only thing God wants us to believe". Rather, it is "the Bible, which is inspired by God, makes the man of God complete and thoroughly equipped for every good work". If the Bible does that, then we need nothing else to be complete men of God. Neither do we need anything else to equip us for good works. Nor is there any good work the Bible does not thoroughly equip us for.
In other words, everything we, as Christians, need, was first preached orally by the Apostles, then written down by those same Apostles, under the direct inspiration of none other than the Holy Spirit. Knowing these things, the Catholic Church was spiritually stillborn. The Apostles, were they alive today, would not be encouraging us to listen to them. Rather, their oral traditions would be filled with harsh condemnations of the Catholic Church.