Fair enough. But let’s not forget that some argue the Didache came out of the second century and it wasn’t found until the 19th century so it stands to reason that it was well rejected… Since it didn’t really exist. At least, we didn’t know where it was or what all of it said.
That is true, although some say the Pastoral Epistles were
written in the Second Century too. That’s really beside the point. Regardless of when the Didace was written, I was just using it as an example to illustrate that date of writing is not an objective criterion that can be used to determine the canon of Scripture. Neither is the tradition of the Church from a Protestant perspective because the authority of the Church derives from Scripture. Calvin is very adamant about this point in his Institutes to counter the papist assertion that the Catholic Church gave us the Bible.
“These ravings are admirably refuted by a single expression of an apostle. Paul testifies that the Church is “built on the foundation of the apostles and prophets,” (Eph. 2:20). If the doctrine of the apostles and prophets is the foundation of the Church, the former must have had its certainty before the latter began to exist. Nor is there any room for the cavil, that though the Church derives her first beginning from thence, it still remains doubtful what writings are to be attributed to the apostles and prophets, until her Judgment is interposed. For if the Christian Church was founded at first on the writings of the prophets, and the preaching of the apostles, that doctrine, wheresoever it may be found, was certainly ascertained and sanctioned antecedently to the Church, since, but for this, the Church herself never could have existed.”
Institutes I.vii.2
Of course, this does not really answer the question since the books of the New Testament are not the same thing as Apostolic doctrine. In actuality, the Church existed before any of the New Testament books were written. Calvin’s underlying point is that the authority of the Scriptures depend not on the Church but on God, which is true. However, this does not imply that the Church derives its authority solely from Scripture since, after all, the Church pre-existed the New Testament. The real question is how Scripture is ascertained. For Calvin, and for all Protestants if they wish to be consistent, there is no objective answer in tradition. Thus, Calvin says in the same paragraph:
“As to the question, How shall we be persuaded that it came from God without recurring to a decree of the Church? it is just the same as if it were asked, How shall we learn to distinguish light from darkness, white from black, sweet from bitter? Scripture bears upon the face of it as clear evidence of its truth, as white and black do of their colour, sweet and bitter of their taste.”
If the Church got things wrong, like indulgences and the papacy, there is no reason to suppose that they could not have gotten the canon of Scripture wrong as well. The only objective way in Protestantism to determine the canon is by private revelation. The alternative is to say that we have a probable biblical canon on the basis of the historical data, which is a concession that few (in my experience) are willing to make.
But to show this to our protestant brothers, it takes more than an affirmation like this one. In fact, I don’t know what it takes 
I think those who never thought about our argument and do not have a strong prejudice against the Catholic Church may be surprised and look into the argument and consider full communion with the Church. Others simply will ignore your argument simply because it comes from a Catholic, and thus it’s got to be wrong.
).
We’ve been married almost 15 years and I’m still praying he will come into the Church, but it is a slow process for him, one small step at a time. He’s closer than he was 15 years ago.