The Church.
Scripture provides for the church, reason, natural revelation etc. Formal sufficiency is limited. But that Scripture is the assured Word of God and transcendent standard for obedience and testing and establishing truth claims, is abundantly evidenced .
Saying it is the church is an assertion. What is the basis for your assurance of Truth? Are you saying that being the historical instruments and stewards of Scripture means they are the infallible interpreters of it, so that dissent from them is rebellion against God? That seems to be the RC polemic behind "we gave you the Bible...)
Then give me one... instead of trying to snow me under with a page full of references that beg the question in that the interpretation of said references assumes your original assertion.
As you can see from the disagreement over 2Tim, passionately asserting a statement is comprehensive does not make it so, not matter how much we wish it. Shaving the corners off a square peg does not make it fit the round hole, even if though it will go inside of it.