You know something that you ignore is the word useful. Paul says that Scripture is inspired and he says that it is useful then he explains how it is useful.
I agree with this.That is, of course the written Word of God has an intent, a purposed outcome, and of course to be " used".
The same can be said of oral teaching, or tradition, council etc.
The two or three can be equal, but only when the latter gets it right, is harmonious with the written, and not the other way around.
Perhaps at the beginning the oral was useful to help determine authenticity of an apostles writing. I mean an early Christian having heard Paul teach would have to say upon later reading his letter, " that certainly sounds like Paul". But beyond that, once a writing is discerned to be inspired, meaning God’s “Word”, it then should become the rule, to be " used" by the Church for all the things Paul mentions ( doctrine, reproof, instruction) leaving the user "competent, thoroughly furnished, complete, perfect, etc.).
but your preconceived religious belief that the Catholic Church does not have authority.
Nothing above states that. Anyone can “use” Holy Scripture to above end. That means, as Jesus even states, the individual can for example reprove someone, as can two together, and finally as can the church, the last being the strongest.
So indeed the CC can and has " used" scripture in 2nd Timothy authoritative fashion. She indeed has in the past used her authority and been quite correctly equal to, in tune with Scriptural intent. Where we disagree is when the Church in my opinion wants more authority than necesary. This I feel is exemplified by continuing to assert that oral ( Her oral, not others) is equal to the Written, or by making tradition a capital unconditionally. Key word is unconditionally. That is to say that her proclamations are always right because she can not be wrong. Only “others” can make “use” of the Word or tradition wrongly.
To be fair , all churches struggle with such assuredness, that it is the church down the street that has it wrong.
It is the Church that has guided us from heresy.
Agree the CC has doggedly fought against heresy. Athanasius comes to mind, like one of David’s mighty men.
It is the Church that shows us what we should believe. It is the Church that Jesus founded. Your position goes against scripture.
I believe to rightly divide scripture one must see the assurances of His perfect guidance ( like strict Calvinists and OSAS?), but also like Arminians that we are to beware, though beginning greatly, and much persevering and reproving others, not to stumble ourselves.