Become God Of This World?!

In a world where a person, who has endured a difficult life filled with sadness, is mysteriously chosen by a god, they are now tasked with overseeing their own civilization. They must perform godly deeds and demonstrate whether they deserve a better life. If they succeed in their divine duties, they will be rewarded with a better life. However, if they fail, they will return to their old life of suffering.