Why does Judah respond by saying that all is in vain

That is in vain! We will follow our own plans, and will act, every one according to the stubbornness of his evil heart. These tragic words are placed on the lips of the people of Judah by the Lord. The Lord is making it plain to both Jeremiah and Judah that his people will not respond to his warning by repenting, but rather by hardening their hearts in rebellion. The sad reality is that people’s hearts can be hardened to the extent that they are beyond repentance and judgment becomes inevitable. Judah has reached that point.¹ The phrase and will act, everyone makes it clear that the refusal to repent is as inclusive as the invitation to repent.² The fatal fault in the clay that is humanity is the sin that is in his heart. There is still a glimmer of hope at this point because the clay can yet be remolded. This hope is all but lost, however, in Jeremiah 19:1–15 where the clay jar is fired and set and has to be shattered.³