What is the main idea/moral/theme of A Lesson Before Dying?

One of the major themes of Gaines's A Lesson
Before Dying is the concept of justice in the face of racism.  The story is
set in a small town in Louisiana, and the residents of the town and surrounding area
harbor racist thoughts towards others.  Jefferson is accused of killing a white man
because he was in the area at the time, and even though evidence suggests otherwise,
Jefferson is found guilty by the jury during his trial.  Further, Jefferson's family
receives a difficult time when trying to visit him in jail.  Jefferson has been used as
a scapegoat for the community's hatred, and this causes him to wonder whether or not God
only loves white people.  While in jail, Jefferson considers his faith, and through
Grant's help, he dies having learned the lesson that he was treated unfairly because
people are corrupt, not because God does not love him.