While I do not agree with RD's over all position taking scripture personally is vital to understanding scripture.
You're position is such that nothing in scripture applies to modern day Christians because it was all written to other people. Your position also says that spiritual advice given to another person is never applicable to others than to whom it was specifically written. Good spiritual advice, like that given to Timothy by Paul, is excellent advice to others too. Otherwise there is absolutely no reason for it to be included in the canon of scripture. All scripture is given by inspiration of God and is profitable for doctrine, for reproof, for instructiun in righteousness, that the man of God may be perfect, thoroughly furnished unto all good works.
It was more than just that 2nd Timothy was written specifically to the man Timothy. It was also written, as was 1st Timothy, and Titus, to bishops. This is a very special gift, that Timothy and Titus the bishops have provided to the Church; literal letters written to them personally, individually, with genuine, from-the-horse's-mouth Apostolic guidance and wisdom. They, Bishops Titus and Timothy, are the men who gave the Church these letters, there isn't any indication that these letters were circulated like many of Paul's other letters, that were copied and distributed, like Galatians, to multiple different Church dioceses /parishes /communities---in order for us to have these letters, the addressees themselves had to provide them for inclusion in the anthology that is the New Testament.
(None of the above should be interpreted to mean that the Holy Spirit is not the author of all Scripture; He surely is, none of this should be taken to mean that it wasn't ultimately the work of the Holy Spirit in ensuring that 1st and 2nd Timothy and Titus are among the NT books either; as it surely is. But He worked through men, namely the Apostle Paul and the bishops Timothy and Titus, in bringing about these books' inclusion in the Bible.)
So the real point is that Paul was writing to a bishop in 2nd Timothy. And none of us are bishops, so it literally is not written to any of us, but surely, to use a common Dispensationalist phrase, it is written
for us, and by us, I mean the Church. There is every reason that the Holy Spirit made sure that 2nd Timothy was part of the NT canon.