I am not arguing the merits of Sola Scriptura, although I would be glad to, I am discussing why and how Jesus instituted a teaching authority within the Church and how even those who reject the need for the Magisterium rely on cheap and unreliable substitutes.
"You have never read Paul’s commendation of the Bereans?"
Of course I have. St. Paul preached the Word on the authority of Jesus, not on his own authority and relied on Jesus' life and ministry being prophesied over 450 times in the existing Scripture available to the Jews of Berea, the Old Testament. If the Gospel Scripture was indeed available throughout the Gentile world at the time of St. Paul's ministry then he would have been no more than the teaching authority.
Show from scripture where Jesus “instituted a teaching authority within the Church”. This whole hierarchy that the RCC has set up is non Biblical.