And exactly what would that "extra-Scriptural" work be? I contend that it was the teachings of Jesus as well as the disciples to whom he both taught and later, through the indwelling Holy Spirit, brought to their memories and further revealed to them. That revelation is contained within the Scriptures and I do not think one bit of truth was omitted from them. We have today what God intended for us to know and have. Every basic tenet of the Christian faith is authorized by Scripture. Any doctrine contrived outside of the authority of Scripture is not and should not be binding upon a believer.
Books such as Hermas, Barnabus and the Didache were some of the list. The whole list? Don't know. I do know this: much of the Church's theology was developed before any NT Scripture was written. It doesn't matter what you or I think. The Church has the authority, not any man.
We have today what God intended for us to know and have. Every basic tenet of the Christian faith is authorized by Scripture.
I think that it would fascinating if you actually found out what Scripture actually says.
Any doctrine contrived outside of the authority of Scripture is not and should not be binding upon a believer.
Ditto.
Preach it, sister.