Cyril of Jerusalem taught doctrines often cited by nonCatholics as unbiblical (purgatory, the Mass, magisterium, etc). Was he a poor exegete to find basis for Catholic doctrine in scripture or was he not really a sola scriptura adherent as you suggest?
It is much more prudent to simply stick with the Word as best we can, neither inventing things not found therein, nor accepting some form of gnosticism, even if it crop up or come from within otherwise respected persons or groups. We see what peer pressure can do.
A new and different Gospel, differing from the original, being a much amended one, is highly suspect.
Was he a poor exegete to find basis for Catholic doctrine in scripture or was he not really a sola scriptura adherent as you suggest?
Take it up with the former Catholic, Webster, whom I was quoting. You may then need address your argument (if you actually have one) to his own cited sources also. Some of them could be easy enough to debate, for they are now dead.
That is exactly the sort of argument the Gnostics brought forth. That they heard or were told things by Apostles that others did not, nor were elsewhere written down. That, and that they received such "secret knowledge" through revelation.
The Early Patristric Fathers smashed them using ---what? Even more "secret stuff"? No, absolutely not. They used the Word. And won those battles!
Go ahead. Place bets on "secret knowledge" given to somebody somewhere, we don't know exactly whom, or where...
I'll pass on that sort of thing...