Sola scriptura means that the Bible is the highest authority, and that Scripture is the final word on everything.
I would use the phrase that Scripture, for that it is true in all things, is the benchmark of all things, but that it is so precisely because we made it so. It is human beings who have determined what is and is not Scripture, that there ain’t no 'Gospel of Peter" as some wish there was, and the Whole Bible DOES SO include Maccabees, even though Protestants don’t “believe it”, and that is because their judgment just ain’t the same as ours, but which is right? Which has the final word? Sola Scriptura defenders say that the Scriptures are self-authenticating, but even as they say it they are making an authoritative judgment and therefore exercising authority over Scripture, so its hypocracy, and a self-contradiction.
But while they say Scripture is the pillar, the authority, it is Scripture itself which denies its authority and says The Church is the pillar instead.
So yes, The Church has final authority. But that does not mean “some individual” is the whole of Church and that that individual, Pope or not, can tell someone to act immorally. No man can authoritatively be asked to act contrary to righteousness. That being said, the Pope, when he speaks “in Union with the bishops” has final authority subject to God, that is, under God’s Providence, God being the sole author of all things.
But let’s do a diagnostic of Scripture. Let’s break down all the logic which can be deduced from Matthew 16.
So there’s Jesus, walking along with his apostles, and he asks “who do men say that I am?”
And the other apostles say “some say elijah, john the the Baptist”, etc.
But then there’s Peter, the slow one, the one we already know ain’t the sharpest tool in the shed, the one who said when Christ died, “well…I guess I’m goin fishing.!”
And Peter says, “you are the Christ, son of the living God.”
And Jesus pauses. “Whoa!”, “even I know you couldn’t have thought that on your own. You ain’t that clever. It must be the case then that My Father In Heaven Has Revealed This To You And Not Flesh And Blood.”
Ergo…God the Father chose Peter first, and Jesus recognizes it, and affirms his Father’s will by adding:
“I tell you, Thou Art Cephas, and upon this Rock I will build My Church.”
So let’s ask: who is doing the talking?
Jesus.
Who is speaking directly to?
Peter
What does Jesus say he is going to do?
Build A church.
Who’s Church?
Jesus’ Own Church, “my Church”, His Church.
and upon whom is Jesus building His very own Church?
Just Peter.
And How Many church(es) does Jesus say he will build for himself?
Just one.
and what is the authority of this Church that Jesus built for himself?
Such authority that whatever Peter “binds and loosed on Earth shall be bound and loosed in Heaven also.”
Wow!
And what else does this Jesus of the Bible say will happen?
What will become of His Church?
Probably exactly what you should expect.
Jesus adds “The gates of the netherworld shall never prevail against his Church.”
Here’s something to pause on…
Where was Jesus, and what was he standing on when he said all this?
He was standing over a very important site to the Romans. A mountain in fact. Precisely, he was standing over a pit the Romans referred to as the ‘Gate to the Netherworld’. It’s was their Golgatha, their Hades, their Sheol, their Hell. Ironically, what the Romans didn’t know is that under this place was the head of the River Jordan. Hmm, very symbolic ya think! Jesus always seems to do what turns everything else on its head.
and just 12 chapters later, in the same book, Jesus adds:
“Teach them to obey all that I have commanded you. Lo, I am with you until the end of Time [era, epoch, age]”
Now, either Jesus was a liar, and he did abandon his Church and he did let it fail, only to bring it back from obscurity after 1,500 years…or he was a false prophet and not really a God at all because his church failed like the Protestants think,
But the only way the Prots can be right is basically, by being wrong. How messed up is that? God, that is, Jesus Christ, either is not God and did not keep his promise to never leave us and never let us fail, or He is, in which case, there is still only One Church that he ever put his stamp of approval on, in fact, it was more than his mere approval, it is the Church he himself built for himself.
Built by Jesu,s for Jesus, with His authority.
Sorry for the long post, but this is no small subject. It was a loaded question, and you opened the whole can by asking it.
But on that point, it is, indeed, a post-apostolic era practice, and I would agree that SS is not explicit in scripture. This is why I would never say that Catholics are condemned for not accepting it. It is a practice (of the [Lutheran] Church for hermeunetics), not a doctrine.