“So answer his simple question. How do you know that 1 Timothy (for example) is inspired scripture?”
1. It claims to be so.
2. It is in sync with other Scripture; does not contradict it.
3. Its claimed author is an apostle, ordained by Jesus to teach and spread official doctrine. Of course, we know of Paul’s apostleship because of the book of Acts, thus as I confess, the reasoning is circular in that sense.
4. The Holy Spirit bears witness with our hearts that is is God speaking to us.
5. It was accepted and utilized as inspired so far as we know, historically, without any known, upheld formal objection.
6. There is no convincing reason to reject it as inspired.
Very well (I won’t squabble with 1, which calls St. Paul’s apostolship willed by God, but doesn’t exactly call the letter itself inspired). So you do not know 1-6 entirely from the Bible. You, rather, base your answer on reason, history, and guidance of the Holy Spirit in “us”. Would that be correct?
Further you answer is spoken from a group: you couch it in plural form and you yourself hardly could have compared every thought in 1 Timothy with every thought in other scripture (2); you personally could not have seen St. Paul convert and preach and your reliance of the Book of Acts is indeed circular (3); you use plural form in (4) and justly so as the Holy Spirit, reasonably, indwells not in you alone; you refer to history which you could not yourself witness in (5); and in (6) you could not personally be informed of every such objection and decide in favor of Timothy 1.
You speak on behalf of a community of believers, don’t you?
In my next question we shall examine what that community of believers must possess in order to ascertain (1-6).
It seems that your argument is that an assuredly inspired magisterium is necessary to establish writings as Divinely inspired, and for that matter, to sanction men of God as having authority. Thus those without it are spurious.