The following quotation is from the character analysis section of eNote's study guide to To Kill a Mockingbird which describes how Atticus is the moral center of the novel.
"Atticus teaches Scout to behave with dignity and compassion; he never speaks down to her, but credits her with the intelligence to understand the point of such lessons as not to judge another person "until you climb into his skin and walk around in it." He explains his treatment of his children to his brother, Jack: "When a child asks you something, answer him, for goodness sake. But don't make a production of it. Children are children, but they can spot an evasion quicker than adults, and evasion simply muddles 'em." Nearly fifty years old, Atticus is older than most parents of Scout and Jem's friends; he differs from many of the adults in Maycomb in that he fights the entrenched ignorance and prejudice of the region. In his private life as a father and his public life as an attorney, Atticus champions honesty, fairness, and respect for the opinions and rights of others. His character seems believable despite his larger-than-life role as the moral center of the novel."
The entire study guide can be found at the link below.