Cronos wrote:
“you do, of course, realise that the “scripture” St. Paul was referring to was the Septuagint?”
Did Paul tell you that? I do not find that in the text of 2 Timothy. Was Paul unable to read Hebrew? Did the Hebrew Scriptures not already exist in the temple archive, thus adjudged already as the word of God, as any decently careful reading, for example, of 1 and 2 Maccabees will bear out clearly? Did the Greek translation of Aquila not also exist? And did not also others? You make assumptions that are, at the very best, doubtful.
As to whether the statement of 2 Timothy 3:16 excludes entirely any already existent NT is a matter requiring considerably more effort than you have made. It is, in fact, very likely that it does not exclude such, and even if it did would not preclude the soon to be added books from inclusion in the same doctrinal application. And as to the oft plainted old saw that the Catholic church determined what was Scripture and what was not, well, that which God gave the apostles and before them the prophets by divine inspiration was Holy Scripture from the moment it was written, whether the Catholic church recognized it to be or not. The determiner here is God. The poor, johnny-come-lately, slow-on-the-uptake realizer is man.