You've created a Catch-22 situation.You don't HAVE to know who they are- but you DO rely upon the teachings they passed down to us.
This is not enough. I'm glad that you acknowledge this much but you have yet to display that you understand that Scripture is not interpreted in a vacuum. That it takes the CHURCH to understand the Word of God properly. That God always intended for us to work together. That even the authors of the Bible worked with each other and those before them and that you have to do the same thing.
The knowledge of God cannot be over elevated.
To know him better is to be further from idolatry- not closer to it.
The problem is the independent mindset that keeps people from REALLY knowing God. Because of this mindset they themselves are idolators fixing a god in their mind to suit them.
Since they lack the humility to submit their interpretations to the scrutiny of the Church, it is THEIR knowledge that is idolatry- because it is not the knowledge of God- it is the knowledge of a god who is the product of ignorance and arrogance.
Someone studies scripture; quotes only scripture; uses scripture as the guide for all they say and do; preaches only from scripture; but your interpretation of them is that, because they haven't submitted their knowledge to the scrutiny of others, they are deficient. In other words, what you've said is that scripture isn't sufficient by itself.