This is a new subject altogether for me, that I stumbled upon today as it came up in another thread, but in trying to understand it and doing some searches in that effort, I found some verses in 1 Timothy.
Paul, an apostle of Jesus Christ, by the commandment of God our Savior and the Lord Jesus Christ, our hope, To Timothy, a true son in the faith: Grace, mercy, and peace from God our Father and Jesus Christ our Lord.
As I urged you when I went into Macedonia—remain in Ephesus that you may charge some that they teach no other doctrine, nor give heed to fables and endless genealogies, which cause disputes rather than godly edification which is in faith. Now the purpose of the commandment is love from a pure heart, from a good conscience, and from sincere faith, from which some, having strayed, have turned aside to idle talk, desiring to be teachers of the law, understanding neither what they say nor the things which they affirm.
But we know that the law is good if one uses it lawfully, knowing this: that the law is not made for a righteous person, but for the lawless and insubordinate, for the ungodly and for sinners, for the unholy and profane, for murderers of fathers and murderers of mothers, for manslayers, for fornicators, for sodomites, for kidnappers, for liars, for perjurers, and if there is any other thing that is contrary to sound doctrine, according to the glorious gospel of the blessed God which was committed to my trust.
So far in my understanding (still very much so a work in progress), this part seems key to understanding where Paul was coming from in some of his other writings. It seems (to me) like the message he was conveying is that prior to coming and sacrifice of Christ, the peoples of the OT times had to rely on "the law" as given to them by God. However after Christ came to the earth and was sacrificed for our salvation, "the law" was replaced by grace and faith and the teachings of Christ.
So going all the way to present day, there are people who have accepted Christ as their savior and have been spiritually saved, and they are following the faith, grace and teachings under Christ. Then there are people who have not yet been saved, have not yet accepted Christ as their savior. So just like the peoples of the OT time who did not have Christ (since Christ had not been sent to the earth yet), and therefore had to rely on "the law" as it was then, people after Christ had been sent to the earth and died for our sins, yet people who had/have not yet received Christ as their savior, would also need to still be relying on "the law" of the OT times.
This makes sense, yes? Christ changed quite a few things when He died for our sins, but that doesn't mean that everyone had/has received Christ as their savior yet. While significant things had changed, each individual was/is still responsible for embracing that transition by embracing Christ as their personal savior. Prior to that, the individual has not made the transition on a personal, spiritual level, and so "the law" still applies.
So for example when Paul was writing instructions to Corinth, it was meant to address several issues that the Corinthian people were having, so perhaps it is because they were having so much confusion and so many issues, that Paul attempted to steer them towards "the law" to play it safe for them until they were to get their issues sorted out.
Does that sound about right, or no?