What happens after we are Justified? Do we then do the work of sanctification? Do we then have to sustain our own salvation by our works?

What should we be doing, or not? Jeremiah 31:31-33 31 “Behold, the days are coming, declares the Lord, when I will make a new covenant with the house of Israel and the house of Judah, 32 not like the covenant that I made with their…