why does the Joad family continue to put their faith in the earth even though the earth has been the cause of their trials ?

The farmer's, and man's, connection to the land is an important theme in The Grapes of Wrath. When the people of Oklahoma are forced to leave their land, this process proves to be devastating. These farmers have been a part of their land and have felt deeply connected to it for years: their hopes and dreams were lost or won in the soil, but now an inanimate tractor plows their onetime territory. The man who drives the tractor never touches the soil or interacts with it, which is a travesty according to the farmers. When the farmers leave, they lose part of themselves. But even beyond the difficulty of leaving their original land, the farmers are unable to create new connections with new land. They are forced to stay on the road, with no places to sleep or live, constantly moving. They are unable to put down roots, and such dislocation is particularly difficult considering their prior connections to set, customary ways of life.