Secondly, from the same verses:
What was Paul referring to by "All Scripture"?
What does "profitable" mean in this verse?
Profitable "for teaching, for reproof, for correction, and for training in righteousness." Note it doesn't say run down to the corner priest to see what tradition says reproof, correction, and training in righteousness. Scripture is profitable.
Here is a little Proddie Secret: let Scripture interpret Scripture. Usually all you have to do is read 20 verses up, and 20 verses down to get the full flavor of any verse. Sometimes it takes a bit more study. But it is all there.