The Apostolic churches love using this verse to prove the importance of their traditions but when you ask them, "What about those infallible traditions which weren't written down...you know, the ones which the Apostle Paul was referring to?", they can't point to any.
That's because the traditions the Apostle was referring to were taught by their spoken "word" and by their written word, (the scriptures). It's pretty clear. If there were "traditions" which weren't written down, then they're lost to us OR, we're forced to believe that not all traditions held by mere men can be held perfectly for 2000 years without being written down! What are the chances of that? Not good when we consider that ALL MEN are fallible.
On the other hand, we DO have what God has meant for us to know via the Apostle's pens, and therefore, we can truly believe that those traditions were written down by what the Apostles taught (verbally) and what they wrote (the scriptures).
On "The Dividing Line", James White response concerning a Roman Catholic apologist who recently commented against Sola Scriptura on a YouTube video. James opens up on a number of issues that come with abandoning the doctrine of Sola Scriptura over the shabby claims of "Apostolic succession".
(You can skip to the 25.00 min. mark)
Irenaeus (late-2nd century):
“We have known the method of our salvation by no other means than those by whom the gospel came to us; which gospel they truly preached; but afterward, by the will of God, they delivered to us in the Scriptures, to be for the future the foundation and pillar of our faith.” – Against Heresies, Book III.
