There are four grades of spirit bones in this world. Everyone else has mortal bones and no chance of cultivating immortality.
The day Chen Jiu was tested and found to have mortal bones, he picked up a mysterious jade slip from a crack between the stone steps. Carved into it was a single line: "The Investiture of the Gods feeds on the incense offerings of the people. Those with mortal bones are not listed on it, and so they can see the truth."
At last, he understood: the so-called gods were nothing but parasites feeding on the incense offerings of mortals. And his mortal bones were precisely the only "flaw" in this world.
Chen Jiu did not go to a sect to work as a menial servant. Instead, he chose Qingshi Town, a small town on the border. Incense offerings had ceased there, and even the gods could not be bothered to set foot in the place. He opened a medicine clinic, repaired irrigation canals, and taught the common people how to save themselves, cutting off the Mountain God's source of incense offerings step by step.
The Heavenly Court was enraged and sent an envoy.
The envoy asked, "You are nothing but a mortal with mortal bones. What makes you think you can oppose the gods?"
Chen Jiu replied, "Because the land beneath my feet does not need a god's charity, because the hoe in my hands is more useful than incense offerings, and because at last, someone in this world has told its people: You don't need to live on your knees."
Those with mortal bones are not on the Investiture of the Gods, so it cannot imprison him.
It's so well written and the story is so touching. It's worth recommending.