Torah keepers say that ALL followers of Messiah need to keep the Torah? Where does the Bible say that?

Torah keepers say that all followers of Messiah need to keep the Torah.

If this is true, how do you address the objection that the New Covenant of Jeremiah 31:31 is a completely New Covenant, which in Hebrew it does in fact say it is completely new (Strongs 2319) and NOT renewed (Strongs 2318):

"Behold, the days come, saith the Lord, that I will make a new covenant with the house of Israel, and with the house of Judah:

32 Not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt"

Most Christians will say the New Covenant is totally different in that it has a Melchizedek HIGH Priest, all covenant members are Melchizedek priests and co-kings with Messiah. There is a different sacrifice that fulfills and in fact replaces all former Covenant sacrifices.

So in what way are we to practice the Mosaic Covenant?

I like the way my mentor Dr. John H. Sailhamer used to say it in summary:

When God brought Israel out of Egyp…