No its a simple fact that follows from the error of sola scriptura.
So...you can't prove it. You can't even give a standard definition of what a denomination is, you won't give what you think is the definition. Your lack of desire to prove your outrageous statement (which has been debunked so many time) takes away credibility in your posts. Even more so when you throw out another controversial straw man argument.
Once again. Where is YOUR solid proof for your outrageous statement.
So...you don't believe everything necessary for salvation can be found in Scripture? That's what Sola Sccriptura is at its heart.
Oh, wait -- you're Catholic, so you just might believe in a "different gospel"
Hoss